Opinions on an Engine Swap for 81 C10

[ceejay]

Right now, I have an extremely tired 305 and I'm ready to swap it out. Now I've bounced around different ideas, but not sure on which route to take. I think I've narrowed it down to wanting a 350. I don't want to do LS swap or big block. I've done some research and I've come down to:

1. Buy a used 350 sbc from same era and slap my accessories on and roll.
2. Buy a Vortec 350 sbc from '97 - '00, possibly swap in a better cam, put carb intake on it and be done
3. Buy a crate 350
4. Buy a used 350 block, get it machined, rebuild it, etc.

The problem I have with 1 & 2 is the motors around me are all 200k+ mile motors and I'm concerned about the longevity.
The problem I have with 3 is price.
The problem I have with 4 is that I've never rebuilt an entire motor. While I really want to learn how to, this is my daily driver and I'd rather rebuild one on the side and take my time and learn.

What would you guys do/have you guys done? Of course I want more power, and I'm trying to stay under $1500 for everything.

Thanks.

 

[Bextreme04]

Right now, I have an extremely tired 305 and I'm ready to swap it out. Now I've bounced around different ideas, but not sure on which route to take. I think I've narrowed it down to wanting a 350. I don't want to do LS swap or big block. I've done some research and I've come down to:

1. Buy a used 350 sbc from same era and slap my accessories on and roll.
2. Buy a Vortec 350 sbc from '97 - '00, possibly swap in a better cam, put carb intake on it and be done
3. Buy a crate 350
4. Buy a used 350 block, get it machined, rebuild it, etc.

The problem I have with 1 & 2 is the motors around me are all 200k+ mile motors and I'm concerned about the longevity.
The problem I have with 3 is price.
The problem I have with 4 is that I've never rebuilt an entire motor. While I really want to learn how to, this is my daily driver and I'd rather rebuild one on the side and take my time and learn.

What would you guys do/have you guys done? Of course I want more power, and I'm trying to stay under $1500 for everything.

Thanks.

I did 4 and am right around $1200 in machining and parts cost. Should be right around 300-350hp and mostly a mild truck/towing motor. Half of that cost was machining work to go .030" over on the cylinders, clean and magnaflux the block and crank, deck the motor .020", fit new pistons on the stock rods and balance the rotating assembly, and do a final cleaning before fitting new freeze plugs and cam bearings. The rest of the cost was new cam/lifters, timing set, oil pump and screen, and all the gaskets. I already had a new balancer, water pump, and distributor that I have replaced on my old engine over the last year and my carburetor got rebuilt about 1 1/2 years ago so I didn't have any of those expenses. If you want to go super budget, you can get a good running vortec motor from the 96-2000 trucks/SUVs and just do a gasket and bearing replacement. Its a roller motor, so you can also just get a new cam or get your original cam reground for dirt cheap without needing to replace the lifters. The biggest issue with getting a vortec motor is going to be making sure it doesn't have a cracked head or blown head gasket as that is very common on those motors/heads.

 

[75gmck25]

Years ago I went through the same debate, and since the GM crate 350 was relatively inexpensive, and I needed my truck back in the road quickly, I bought the basic crate 350 (about $1,800) and moved all the accessories over. Although its a quick solution, and relatively inexpensive for an engine with a 3 year GM warranty, it was not really the best solution in the long run.

Disadvantages of using an inexpensive crate engine:
- Usually have original GM design iron heads (very poor flow), very mild flat tappet cam, 2 piece rear seal, low compression
- Power is very similar to your original smog-era engine - feels like you spent quite a bit of time and money and didn't really get much for it.
- When you decide you want more power, you really need to start out with better heads and try to increase your compression - not a cheap upgrade at that point

If I was going to do it again I would consider this path.
- Find a good junkyard engine that is already set up for a roller cam. My preference would be a late 90's Vortec 350 with known good heads, or one with cracked heads that I could get really cheap because it had bad heads.

- The reason I like the Vortec 350 engines is that they had a very good EFI setup that kept them from running too rich. You can find some blocks with 100k miles that are so clean in the cylinders that they just need a mild hone. Older roller-ready TBI engines would also be okay, but its not worth keeping the heads.

- Have a machine shop clean up and inspect the block, and make any necessary repairs (maybe none needed). If its a Vortec it probably already has decent compression (9.5?), so maybed all you want is new rings. Either have them cleanup and do a valve job on the good Vortec heads that come with the block, or if they are cracked, then replace them with budget aluminum heads.

- Pick out a roller cam that suits your planned use of the truck. Big rump-rump cams sound mean, but gas mileage usually sucks and you need low gears and rpm to make them work. I chose to use a 213/217 @ .050 duration cam because I need the pulling power for heavy loads, but you can go either way.
- Choose a good intake and carburetor, or consider EFI if you have deeper pockets.

Bruce

 

[dsteelejr]

Right now, I have an extremely tired 305 and I'm ready to swap it out. Now I've bounced around different ideas, but not sure on which route to take. I think I've narrowed it down to wanting a 350. I don't want to do LS swap or big block. I've done some research and I've come down to:

1. Buy a used 350 sbc from same era and slap my accessories on and roll.
2. Buy a Vortec 350 sbc from '97 - '00, possibly swap in a better cam, put carb intake on it and be done
3. Buy a crate 350
4. Buy a used 350 block, get it machined, rebuild it, etc.

The problem I have with 1 & 2 is the motors around me are all 200k+ mile motors and I'm concerned about the longevity.
The problem I have with 3 is price.
The problem I have with 4 is that I've never rebuilt an entire motor. While I really want to learn how to, this is my daily driver and I'd rather rebuild one on the side and take my time and learn.

What would you guys do/have you guys done? Of course I want more power, and I'm trying to stay under $1500 for everything.

Thanks.

Why not just buy a reman long block? I'm in Wyoming, but there is an engine rebuilding company here that will sell you a four bolt main 350 short block for $1050 or a long block for $1500.

 

[82sbshortbed]

BBC

 

[Bextreme04]

BBC

This is obviously the only acceptable answer...

 

[Paladin]

1.
2.
3.
4.
5. Big Block it and forget it!

 

[ceejay]

@Bextreme04 I guess it's more tempting now to get machine work done because with all the stuff that you listed, I thought it would cost more. 300-350HP is about what I'm after, but more concerned with torque. I've seen some junk Vortec 350s for about $300 around me, but alot of miles.

@75gmck25 Yeah, the Vortec motors look good. Like I said, I've found a few around me, but definitely feel like regardless I'm going to have to get machine work done and hopefully find one with good heads.

@Paladin @82sbshortbed If it weren't a daily driver, I would agree with you as a viable option. I'm trying to keep somewhat decent fuel economy.

 

[Bextreme04]

@Bextreme04 I guess it's more tempting now to get machine work done because with all the stuff that you listed, I thought it would cost more. 300-350HP is about what I'm after, but more concerned with torque. I've seen some junk Vortec 350s for about $300 around me, but alot of miles.

@75gmck25 Yeah, the Vortec motors look good. Like I said, I've found a few around me, but definitely feel like regardless I'm going to have to get machine work done and hopefully find one with good heads.

@Paladin @82sbshortbed If it weren't a daily driver, I would agree with you as a viable option. I'm trying to keep somewhat decent fuel economy.

The trick is going to be finding a decent core. If you can find a good core 96-2000 vortec 5.7L, you probably wont need anything done except for refreshing the heads and cleaning everything up. If it is a daily and you want that power level and reliability, you really probably want to re-evaluate an LS swap. They are dirt cheap to get the motor in your area of the country and several companies make all inclusive "swap kits" that give you everything you need to drop it in.

 

[ceejay]

The trick is going to be finding a decent core. If you can find a good core 96-2000 vortec 5.7L, you probably wont need anything done except for refreshing the heads and cleaning everything up. If it is a daily and you want that power level and reliability, you really probably want to re-evaluate an LS swap. They are dirt cheap to get the motor in your area of the country and several companies make all inclusive "swap kits" that give you everything you need to drop it in.

Idk. I just feel like when I pop the hood it's more natural to see a 350/454 under it then an LS Swap. It's not like I loathe LS Swaps.

 

[SquareRoot]

Save your money until you can afford option #3. Buy once-cry once.
Carry on

 

[ceejay]

Save your money until you can afford option #3. Buy once-cry once.
Carry on

Is there a brand of crate you would recommend? Blueprint? GMPP?

 

[SquareRoot]

Both of those are good. I generally view quality by thier Warranty. I would focus on the short block components and machine work. The rest is just bolt on parts.

 

[Catbox]

My kid went to the junkyard and called me early in the morning.
"Dad, I found a Vortec big block with a 4L80 transmission attached."

It just so happened to be 50% off everything day.
So for a total out the door price of $445 I have a roller big block and a big ass 4 speed transmission to go with it.
I also picked up the driveshaft that came from the truck too.

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With @Bextreme04 's $2500 rebuild cost for the engine (see his build thread) and another $1500 for the transmission you would be set to go.

While not the cheapest route, it is another viable option.

Or you could do a simple refresh on the engine and slap it all in your truck.
A few hundred bucks more and you are there with refreshed goodies.

At the swap meets I have found a used intake for $125 and a nice Holley carb from a buddy for another $100.
For exhaust we are now running a set of free headers, not pretty, but free.

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[idahovette]

@Catbox Jees Peter, that kid is worth his weight in gold, comin up with all these deals. I know you're paying, but do you tip HIM??....LOL