350 or LS

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Cruck

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350. That is what belongs in that truck. Bolts right in, no computer or sensors. JMO, many others will speak differently.....

It actually came with a 6 cylinder. I inquired about doing that but so many have advised against it. It will have more power than it originally had and is a bit more modern. Not sure why it was frowned on.

Compare milage on vortec suburban vs. ls suburban. Almost identical. Do injected SBC trucks start right up and drive? Yes. Did millions if people count on 350 burbs and Escalades as mom and kid transportion? Yes. SBC is reliable and not horrible on fuel with modern engine management. Buy a 5.7 lt1 roadmaster (lt1) swap in the engine,transmission ecm and engine harness. Cheap fuel injection,good engine management,and it's a bolt in. Or swap in a complete TBI or Vortec drivetrain. Including engine management.If your real goals are just easy,reliable,and decent mpg. If just an occasional driver stick a good carbureated 350 in it and call it a day. The difference in cost will pay for a lot of fuel. And people counted on carbureated 350s for decades,to run business, get to work, cross country on vacations. We still had vehicles we could count on ,before LSs

I read about adding vortec headers to the 350 block and modern fuel injection instead of a carb. How much more fuel efficient would that be?

My 350 was tired and worn out, took it out and had the shop bore it and made a 383 stroker. I love the way carb engines sound at idle. I did think about doing a LS swap, but making a 383 came out way cheaper then doing a LS swap and way easier. But honestly its your truck, do what you want.

This 383 idea sounds good. How much more power would it have? Would the fuel mileage be better?

Budget and capability of the folks doing the work is key. As is how many miles you plan on putting on it.
From my point of view, LS swap for a few reasons.
1 fuel mileage if you plan on alot of miles and going as far as swapping in an OD trans.
2 fun factor. You’ll spend as much or more from my research building a 350 small block that will rev like a stock LS and have the power that a LS with bolt ons will have.
3 being unique. IMO LS swap is still unique and not the norm.

Downsides are it is more complicated as is your situation of what the volunteers are willing to do for you.
I’m in the active contemplation phase of what I ultimately want to do with the powertrain in the 77. Difference being, it has a turn key new 350 under the hood and a fresh rebuilt TH350 that I could drive from here to your house with nothing but a gas card.

All that said, based on your first post, the bigger picture question is what is the truck going to take to get it to where you want it to be?
When you throw out terms like trashed, flooded, rusted out, that sounds like the trifecta of either becoming a parts truck, recycled metal or a complete restoration.
I view “projects” like this in 3 categories.
The “clean, runs, decent shape” only need “100 things”.
The “projects” need “1000 things.”
And a vehicle as you described needs “everything.”
As you’re admittedly new to this without any past frames of reference, this truck sounds like somewhere between the hypothetical 1000 things and everything. Simply because your untrained eyes are able to identify several major issues.
Quick numbers, bought the 77 this past year. Basically as it sits now. The PO resurrected it from 20-30 years of sitting, not flooded, not trashed, not rusted and all in one piece, fired up and limped it home. He is not a mechanic. He gave me $15k in receipts for a truck that has a reman stock engine with new accessories (mostly), stock rebuilt trans and new tires and brakes. Just a quick summary of how costs add up and how they add up to 3x as much when you hire out the work. That $15k includes $0 for body, paint, electrical, interior. It’s nothing but drivetrain and running gear work. And that work was done to a truck that was already in great original shape. IE no surprises or difficulties.
And he never even changed out the original diff fluid! lol
Not trying to dissuade you here, but rather get you to think about the whole process and not just the vroom vroom under the hood. That’s actually the easy part.

That is a lot of work and MONEY!!!

If your truck is in good shape, LS swap is cool now, but 20 years from now it will be a classic truck with the wrong engine.

Great point!!!

Based on your experience level, and the expertise of your crew, a mild 350 build would seem to make the most sense. Lots of info and all kinds of parts available to fit any budget.

The weakest points of the early GM 350 are poor flowing smog-era cylinder heads, low compression, and old design flat tappet cams that don’t mix well with modern oils. All the early 350’s have these limitations, even the mythical Corvette engine that someone's buddy wants to sell you for $***.

My suggestion is to start out with a Vortec 350 (it was the stock engine in mid 90’s and up), or plan to swap heads to use Vortec iron heads or a budget aluminum head. Also plan to use a roller cam (Vortec 350 already has one), or a roller cam conversion. Using that as a basis, it’s easy to build a reliable 325-350 HP 350 with very good street manners.

Someone mentioned to me that I should be using a block stamped 010. Is that a better version on something?

So I am taking a rebuilding class at the local community college. Not the one that is doing the work. I live in the Pacific Northwest and the truck is in the south. I have a running F100 here that is rather tired. It runs and drives but the engine needs a rebuild. My instructor suggested I do a 350 along with my F100 engine. He seems to think even with the cost of shipping the engine I would come out ahead.

The primary use of this truck will be get around when I go home. I head south 2-3 times a year. I am generally there a month or so. No hauling or heavy work in it. Mostly so the folks can stop complaining when I go more than 60 miles in one of their cars. My dad will probably drive it sometimes but not much.
 
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DoubleDingo

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Sixes are reliable. People don't like them because they're not v8. Decide which direction you want to go, block out the bs, and enjoy the rig.
 

Ricko1966

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It actually came with a 6 cylinder. I inquired about doing that but so many have advised against it. It will have more power than it originally had and is a bit more modern. Not sure why it was frowned on.



I read about adding vortec headers to the 350 block and modern fuel injection instead of a carb. How much more fuel efficient would that be?



This 383 idea sounds good. How much more power would it have? Would the fuel mileage be better?



That is a lot of work and MONEY!!!



Great point!!!



Someone mentioned to me that I should be using a block stamped 010. Is that a better version on something?

So I am taking a rebuilding class at the local community college. Not the one that is doing the work. I live in the Pacific Northwest and the truck is in the south. I have a running F100 here that is rather tired. It runs and drives but the engine needs a rebuild. My instructor suggested I do a 350 along with my F100 engine. He seems to think even with the cost of shipping the engine I would come out ahead.

The primary use of this truck will be get around when I go home. I head south 2-3 times a year. I am generally there a month or so. No hauling or heavy work in it. Mostly so the folks can stop complaining when I go more than 60 miles in one of their cars. My dad will probably drive it sometimes but not much.
If you're not rebuilding your engine,then you do not want to start with an 010 block,thats an old high nickle,flat tappet block.You want to Start with a roller cam block. Adding vortec heads( not headers) without adding Vortec or other port fuel injection, isn't what I'd recommend unless you live somewhere where it never gets cold.Theres other heads that would be more suitable. The 383 will add about 10 percent more HP and Torque than an equally built 350,and about the same decrease in fuel economy,you will feel the difference. Fuel economy difference going EFI won't be huge,but it will start and run like a modern car,and you need port fuel injection,not tbi,not carbureator if you run vortec heads,unless it never gets driven in the cold. On a budget,again I'd pull a running 350 and 700r4/4l60e,fuel injection,ignition,ecm and engine harness from a 350 vortec or 350 lt1 or 88 up 350 TPI. Very likely get away with rings,bearings,valve job and gaskets. If you need to buy a crank and pistons,anyway,then step up to 383. There is no reason to replace or regrind a good standard/standard crank. If it's out if spec that's when to consider an upgrade replacement. Unless of course the goal of a dependable driver with decent mpg and turns the tires occasionally isn't the real goal, in which case do the LS swap
 
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bucket

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It actually came with a 6 cylinder. I inquired about doing that but so many have advised against it. It will have more power than it originally had and is a bit more modern. Not sure why it was frowned on.



I read about adding vortec headers to the 350 block and modern fuel injection instead of a carb. How much more fuel efficient would that be?



This 383 idea sounds good. How much more power would it have? Would the fuel mileage be better?



That is a lot of work and MONEY!!!



Great point!!!



Someone mentioned to me that I should be using a block stamped 010. Is that a better version on something?

So I am taking a rebuilding class at the local community college. Not the one that is doing the work. I live in the Pacific Northwest and the truck is in the south. I have a running F100 here that is rather tired. It runs and drives but the engine needs a rebuild. My instructor suggested I do a 350 along with my F100 engine. He seems to think even with the cost of shipping the engine I would come out ahead.

The primary use of this truck will be get around when I go home. I head south 2-3 times a year. I am generally there a month or so. No hauling or heavy work in it. Mostly so the folks can stop complaining when I go more than 60 miles in one of their cars. My dad will probably drive it sometimes but not much.

Don't worry about finding a 010 block. Back in the day, it was a "better" block due to the high nickel content. But it's probably also the most common block you will find. These days, a newer block with roller cam provisions is a far better choice for most people's needs. Most truck blocks from '87-up are designed for use with a roller cam, but not all were. '87-'92 Camaro, Firebird and Caprice 350's all came with a factory roller cam. The Camaro and Firebird heads in those years aren't great by today's standards, but they are capable of decent performance and use a standard type intake manifold (other than the center bolt hole angle, but that's very easy to overcome). '96-up trucks got the "vortec" block and they all had a roller cam. There are some minor differences (like the water pump bypass hole) but are a great starting point. They also come with the "vortec" heads that are one of the best flowing, stock type iron heads that the small block ever got. However, they do take a specific intake manifold and gasket design, and they also limit you in your cam selection due to valve guide clearance.

Beyond that, you're going to get all kinds of advice on what direction to take your build. There's about a million ways to build a 350, you just have to figure out what fits your needs the best.
 

Cruck

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Ok!

I found a vortec from 97 1500 with a thrown rod in #7. Seller says block seems fine. Only wants $100 but lives about 3 hours away. Is it worth the drive?
 

bucket

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Ok!

I found a vortec from 97 1500 with a thrown rod in #7. Seller says block seems fine. Only wants $100 but lives about 3 hours away. Is it worth the drive?

An actual thrown rod? Or just a bearing?

If it's a 100% complete engine with accessories and all, it ain't a bad price. Depending on how much fuel you go through getting it. Maybe not worthwhile as a builder, but worth it for the heads and accessories.
 

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Ok!

I found a vortec from 97 1500 with a thrown rod in #7. Seller says block seems fine. Only wants $100 but lives about 3 hours away. Is it worth the drive?
It's definitely worth 100.00 if only just for parts. You need to determine what your time and transportation costs are worth to you.if that block and heads are usable you are off to a good start. I'd see if I could find a used TPI set up and vortec runners.And since it's going to need a crank anyway,this would be a good time to consider building a 383. A 383 with Vortec heads and TPI would be a Torque monster for a small block.
 
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Tyger13us

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357ci/Hei/flat tappet cam/10:8 compression on pump gas/Iron eagle 64cc chamber heads/1405 edelbrock re-jetted and rods,, 14.0 Afr down the road "flat land" 370ish hp/350Th/205/373's/31x10.5x15's.
i get 18-20 mpg, singing down the road @ 3k rpms the way it was designed.
it hauls ass and the mail also.
Easy to work on compared to ANYTHING Ls........
No computer for the win...
a bad injector wont end well...
 

hdchevy

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We get these old trucks because we like the old truck. Nothing like a SBC 350. I know there are all levels of customizations out there and to each his own but an LS swap is not for the faint of heart or easy one the bank account. I would say get a crate 350 SB and let the kids install it. They have probably never been around one and it would be a good way to get them some hands on experience without all the risks of an LS swap.
 

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I suggest a stock rebuild or crate engine. Use the savings to have the transmission and rear end rebuilt. You stated that the truck was flooded.
 

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Howdy to all Squarebody owners just wanted to share my opinion in regards to the 350 sbc or Ls?
Well for starters let's just say I'm not a fan of Code readers or having to hook up a laptop to tune in vehicles I have owned a few vehicles and most of them had 350's in them also had a few with 454's as well I myself would go with a 350 small block I have 2 C20's both with 350s like that everything is affordable & lots parts availability Etc. But if you want a monster for towing or moving big items put in a 454 big block just my 2 cents
 

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Vbb199

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Keep it a 350

You and your buds can have another one in the truck in a weekend

Sincerely signed a 30 y/o guy who loves, tunes, and fixes modern fuel injection, but also loves and owns the simplicity of pre FI stuff
 

Cruck

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After a bit more reading and learning, I came across the LFX and LF3. These are 6 cylinder engines that in Cadillac and Camaro. They push over 300 hp and torque while getting over 20mpg. Personally this sounds like a great option. However, this is to the new guy that doesn't have much experience. Is there any reason why I would not do this other than it not being the "cool" thing to do. The original 6 cylinder had only 110hp.

What would an LS cost in parts/supplies? I am not thinking about the labor. I have working to try to figure out what actual parts I would need.
 

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My estimate on LS swaps used to be $2000 plus the cost of performance or maintenance parts, plus the cost of transmission but including a junkyard 5.3. That would at least get into the ballpark. Now, thanks to inflation etc, I think you should probably start at $2k plus your engine and transmission costs, assuming you are going for stock power level (and there's ZERO wrong with that).
Baffled fuel tank and new pump/sender, something like nylon fuel line or making the factory hardline work, a reworked factory harness and modified tune for VATS and various delete (again, does not include performance tune), adapter plates, and misc pieces for hoses, intake tube, radiator, cast iron manifolds, etc. That's probably an aggressive budget for most, but other guys are going to say that they did the same swap for less than $1000 all-in, so I think it's fair. That's no labor, used/wrecking yard parts, and not much in the "might as well do this" category, but it will get you running and driving just like the 180k mile Yukon or whatever you pulled it out of...

When you look at swap budget breakdowns, you really need to look at it from a Required/Performance/Looks breakdown. If you want it to look nice, then you are going to add $500-1000 for breaking the engine down, cleaning everything, painting the block, reassembling with new gaskets, shaving the factory intake manifold, nicer filter setup, braided fuel lines, etc. If looks aren't a major factor, then most of the parts attached to it in the junkyard will do just fine, just spend a couple minutes with a can of Gunk to keep your hands cleaner while you work on it. That money isn't part of the swap, it's part of dressing the engine up.
Same for performance, if 300 hp is fine, grab any 5.3 and have fun. Some folks will have $5k in cam/heads/intake/headers etc. and call that part of the swap cost, where it really isn't. Making a plan is critical, most $10k+ swaps will have had a point in them where the owner changed their mind and subsequently had to re-buy parts because something didn't work with another part of the build, or a case of the "OOOOH! Shiny!" hits and they ditch the 4L60e they just built up for a T56 or something like that. Of course those can happen, and can be a good change. But don't let the total budget for something like that scare you, that's a Change Order in the business, and should not affect creating an initial budget that you plan to stick to.

If you stray farther and go into "non-standard" swap engines, you will be in uncharted territory. It's entirely possible that the factory manifolds from the Camaro V6 will fit in a truck chassis, and simultaneously possible that no combination of anything previously made will clear in your truck, and a $2000 set of custom mid length headers is the only option. Same for transmission options, maybe you can stab a regular driveshaft in and be good to go, or maybe you have to find a driveshaft from a 2008 Solstice GXP and mate it with a 2004 ElDorado halfshaft to make things work, and it's hard to say before you just dig in. Obviously I'm just making that up, but the point is that you don't know what you don't know on a one-off swap.

If you like the thought of a 6 (and who doesn't, especially if the truck was originally a 6 anyway) check out the Vortec 4200 straight 6 from the Trailblazer. It has a little more aftermarket support for swaps, and can make similar power to stock 4.8/5.3. There's a few folks running them in square's, but it would still be on the front edge of things. There is more support for the swap in general than for any modern GM V6's, but still much less than for a V8. Being a truck that was designed for a straight 6, I wouldn't think you would have too many fitment issues, but part of the fun is finding out...
 
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Zelph

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After a bit more reading and learning, I came across the LFX and LF3. These are 6 cylinder engines that in Cadillac and Camaro. They push over 300 hp and torque while getting over 20mpg. Personally this sounds like a great option. However, this is to the new guy that doesn't have much experience. Is there any reason why I would not do this other than it not being the "cool" thing to do. The original 6 cylinder had only 110hp.

What would an LS cost in parts/supplies? I am not thinking about the labor. I have working to try to figure out what actual parts I would need.
 

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