Building a new motor for my 79 C10 - would love some advice!

Sorry for the long post!

First things first, this is basically my first motor build & I'm kind of learning all this stuff as I go. I'm having a machinist fix up my block - said it'll need to bored over, and he said he'll clean up my stock crank & rods too.

I'm looking to push some more horsepower, definitely not more than 400 - ideally somewhere around the 350 mark. I want to have good low end power, since its going in a long bed pickup - and want to make sure I maintain enough vacuum to run my power brakes.

Some info about the motor as it sits - 1995 350 TBI motor out of a van (this is about all the info I have, my Grandpa put the motor in the truck 15 years ago). I've currently got a Weiand Street Warrior intake manifold (will need to be replaced with new heads) and a Edelbrock 600 (or 650, I'm not totally sure at the moment) CFM carb.

My machinist is going to order the pistons, bearings, etc. just to make sure everything matches up - and I mentioned that I'd like to bring the compression up while still using pump gas, so probably around 9.5:1 or so (per what the machinist said)

Here's where I get lost and have read so much conflicting information I figured I'd just ask around on here.

I'm looking at getting some aftermarket heads - was eyeing the Brodix IK180s (64cc chamber, 180cc intake runner, 2.02" intake valve, 1.60" exhaust valve) anyone have experience with these? Would they be adequate for my HP goals?

I also have ZERO clue about camshafts - I have been researching for days and am just not sure - was probably going to go ahead and call COMP to get their thoughts. The heads are my main concern, since I want to get them ordered so I can drop them off at the same time as my block, just so the machinist can check them over.

Appreciate any advice!

What is 90 percent of your driving going to be.Whats the truck going to be used for?

68dhayes said:

Sorry for the long post!

First things first, this is basically my first motor build & I'm kind of learning all this stuff as I go. I'm having a machinist fix up my block - said it'll need to bored over, and he said he'll clean up my stock crank & rods too.

I'm looking to push some more horsepower, definitely not more than 400 - ideally somewhere around the 350 mark. I want to have good low end power, since its going in a long bed pickup - and want to make sure I maintain enough vacuum to run my power brakes.

Some info about the motor as it sits - 1995 350 TBI motor out of a van (this is about all the info I have, my Grandpa put the motor in the truck 15 years ago). I've currently got a Weiand Street Warrior intake manifold (will need to be replaced with new heads) and a Edelbrock 600 (or 650, I'm not totally sure at the moment) CFM carb.

My machinist is going to order the pistons, bearings, etc. just to make sure everything matches up - and I mentioned that I'd like to bring the compression up while still using pump gas, so probably around 9.5:1 or so (per what the machinist said)

Here's where I get lost and have read so much conflicting information I figured I'd just ask around on here.

I'm looking at getting some aftermarket heads - was eyeing the Brodix IK180s (64cc chamber, 180cc intake runner, 2.02" intake valve, 1.60" exhaust valve) anyone have experience with these? Would they be adequate for my HP goals?

I also have ZERO clue about camshafts - I have been researching for days and am just not sure - was probably going to go ahead and call COMP to get their thoughts. The heads are my main concern, since I want to get them ordered so I can drop them off at the same time as my block, just so the machinist can check them over.

Appreciate any advice!

Click to expand...

If you are looking for a daily driver engine and not using it for making your penis bigger... then a simple "RV" cam and a set of headers is the most bang for the buck you can put in your engine compartment. The combination is known to be the most reliable, power increasing, mileage increasing, low cost upgrades you can do on a 350. I'd stick with the carb you have unless you want to destroy your mileage for just a few more horsepower.

Here is an easy way to make sure the parts all match.

It's a little pricey but your almost guaranteed the advertised performance. There are more levels and other manufactures that offer the packages. I think GM still offers a Vortech package, but it is too much money in today's world.

Consider the total cost of upgrading a milquetoast engine before spending the money on it and compare to what you can buy, pre-assembled with a warranty, imo.
Case in point, PO of my “new” C10 spent $7500 to get the same chitty 180 hp engine he had before. For $7500, I would have 500-600hp under the same hood.
Just a consideration to get the most hp per $.

What is your gear ratio in the rearend?

It all depends on what you are wanting to do with it.

I will be building a 350 for my car here in a bit.
I want it to be able to drive across the country as well as have some fun with the throttle.

For heads, if it were mine I would stick to the 180 to 195cc intake port range.
Myself, I am going to use a set of these from AFR:

"Our new 195cc SBC Enforcer cylinder heads are a budget friendly offering that is available as a “No Parts” head or can be ordered fully assembled with the same great components found in our higher end cylinder heads; such as ARP rockers studs, PAC Racing springs, AFR adjustable guide plates and our Stainless Steel valves.

These heads come with an As-Cast surface on the intake runners, exhaust runners and combustion chambers. They are a perfect choice for anyone looking to upgrade from the factory Iron pieces. Available in straight or angled spark plug configurations. Sold as a single piece, 2 required per engine."


A cam is more difficult to point you at without more information on driving habits and what you want to live with.
This is a simple cam that states it has strong torque and smooth idle:


For the middle of the road and does everything pretty well, this one seems to be good.


I prefer something a bit spicier, so I might go with this one depending on the use of the truck.


For my car, this will probably be in the range of duration and lift I will be looking at.


"Xtreme Energy™ 224/230 Hydraulic Flat Tappet Cam for Chevy Small Block. Very strong torque with excellent mileage and a smooth idle. Xtreme Energy Cams™ bridge the gap between Magnum street cams and race only cams. Xtreme Energy Cams™ provide increased torque, vacuum, response, and power while still providing quiet operation of the valve train and the durability required in daily driven vehicles.

Includes Cam, Lifters, & Timing Set

Xtreme Energy™​

Benefits:​

• Quicker opening lobe profiles deliver increased responsiveness & more area under the lift curve
• More vacuum allows a step up in duration for greater performance
• Best seller; excellent all around performance in street carbureted applications

Important Considerations:​

• Work best with COMP Cams® roller rockers and matched valve springs
• Require other performance parts (intake manifold, headers, etc.) for best performance

• Dyno Results​

  Camshaft Part #​	12-242-2	Designation​	XE268H-10
  Duration @ 0.006":​	268° / 280°	Duration @ 0.050":​	224° / 230°
  Max Lift w/ 1.5RR:​	.477" / .480"	Lobe Separation:​	110°
  Lobe ID#'s:​	5443 / 5203	Intake Centerline:​	106°
  Engine Type:​	Chevrolet 350 Small Block
  Bore:​	4.040"	Stroke:​	3.480"
  Displacement:​	356ci	Compression:​	9.25:1
  Heads:​	Dart S/R	Intake:​	Edelbrock Performer
  Carburetor:​	Holley #3310 Vac. Sec.	Exhaust:​	1 5/8" Headers
  Max Torque:​	413 ft*lbs @ 3800 RPM	Max Power:​	342 HP @ 5000 RPM
  Manifold Vacuum:​	15.5" Hg @ 800 RPM & 17" Hg @ 1000 RPM w/ no load.

There are 1million ways to build one and we all have different needs and wants out of them.
That is part of what makes playing with them so much fun.

What I want for my lighter than your truck car might be a dog or under impressive in a heavy truck.
But in my 3400 pound car, it might be that tire frying fun we all want.
Do some reading and ask loads of questions to start forming your own opinion.


But what ever you do, do not reuse those swirl port heads.
They suck.
My 1995 Suburban has a set and they are done flowing at 4,000 rpms.
A massive 200hp and 300ftlbs from the factory in a 6,000 lump of steel is not the most exciting thing.

Currently have an engine at a machine shop as well, so just went through the process of choosing parts for low end power for towing and daily driving (no racing).

Regarding cam shafts, look for something with minimal overlap. They are a bit tough to find, but something close to 114 degrees of lobe separation is good. Cams with 110 degrees of separation will produce more top end power, a rough idle, and racing guys love them.

To calculate overlap: take the advertised intake duration + advertised exhaust duration. Divide that number by 4. Then subtract the degrees of lobe separation. Take that number and multiply by 2. Thus will be your degrees of overlap. Somewhere between 30 to 40 is good for a daily driver with focus on low end torque. Racers want more overlap to utilize exhaust flow to draw more fuel in and bleed off a bit of compression.

A daily driver engine doesn't run well with big valves and big intake. The reason is there isn't enough velocity through the intake at low RPMs. If you are wanting low RPM power (less than 5k), stock style intakes with long runners increase the air velocity below 5k RPM. Big intakes need to be over 5k RPM to produce velocity and power. If your velocity is too slow and intake duration too long (your piston going back up before the valve closes), your air and fuel mixture will actually get forced back out of the cylinder. To solve this, you either need a smaller intake or shorter duration on the cam. Exhaust works on a similar principle.

I would suggest a roller cam. They are more expensive and will require some differences in rockers and springs, but your machinist should be able to make recommendations for you to match whichever cam you choose. I went with a roller cam and needed a retrofit kit because it was an old flat tappet block.

Be careful when chasing HP numbers. It all depends on where you want your power. If you watch YouTube videos showing before and after dyno graphs, the stock cam almost always produces more power below 5k RPM. If you are wanting to race on the weekends, that is a very different cam then something that is only going to be a daily driver.

Ok, i own two of these trucks, 84 long bed with 373 gears. Took an327 crankshaft with the updated 327 cam and that thing will turn rpms all day. Plus it has great vacumn and no issues at all. The second truck, 81 stepside, put a 4 bolt main out of a 70 chevelle ss. Bought it cheap as everyone wants a LS motor. Put the edlelbrock complete top end on the motor. heads roller rockers the cam intake and avs2 carb. About 430 hp. It will haul butt. 321 gears. The 84 is about 325hp. both are great trucks to drive. The edelbrock kit is awesome and everything is already thought out. I would highly say that is the ticket. The other setup is not as costly and most of it is just stock chevy parts. You buy the vortech heads pretty cheap and they run great. It all comes down to how much money you want to spend. Bob

Some general guidance- start out with better heads and higher compression.

- Original smog heads are very poor flow. Better flowing heads will make everything work better. Lots of good choices out there, including the L31 Vortec iron heads. Don't bite on the idea of using somebody's used "Corvette heads" or other performance heads from the 60's. Modern heads work better. And you can't fix your stock heads - in general, they really suck.

- Original compression is about 8.2 with stock dished pistons. New pistons in the range of 9.5 compression work much better and are still fine with regular gas.

- Highly recommend a retrofit roller or stock full roller cam (your block may be drilled for it). No more worries about flat cam lobes, and the specs of the valve opening and closing is much more flexible when choosing your cam.

- Cam specs you want will depend on the weight of the truck, gearing/tire size, and where in the RPM band you want your power. Original cam duration was probably about 192-195 @ .050, and when someone recommends an RV cam it usually means a duration of about 214-218 and LSA of about 112. This type of cam provides higher power, but you still have a very smooth running truck in normal driving. It should easily do 325-350 horsepower with good flowing heads, 9.5 compression, headers and dual exhaust.
Once you get above 220-225 @ .050 cam duration the horsepower will be higher, but more "peaky". It will also start to have a more "rump, rump" sound, which many folks like. However, it may actually lose low rpm power, which is bad when you need to get a heavy truck moving.

- Intake should be a good dual-plane like the Edelbrock RPM or similar design.

- For carburetors everyone seems to have a favorite. The Edelbrock AVS is probably the simplest choice to tune, but Quadrajet and Holley can be tweaked more if you know what you are doing.

- Unless gas mileage is your big priority, find some 3.73 gears and swap out what you have (stock might be as high as 2.73 or 3.08).

- San Antonio pick and pull used to have a lot of squarebody trucks, and Roosevelt auto parts was also a good source, but its been a long time since I've been to either one.

Get David Vizards book on small block chevys. Study and learn. Just small details that you can do, can make more power and more reliability. But I like to study before I spend money. It comes hard.

You have received plenty of information on this engine. By the time you are done putting in all the parts you will be around 5 to 600 hp. It doesn't take much to make a 350 have 350hp and it wouldn't need aluminum heads but its up to you. Good luck

68dhayes said:

Sorry for the long post!

First things first, this is basically my first motor build & I'm kind of learning all this stuff as I go. I'm having a machinist fix up my block - said it'll need to bored over, and he said he'll clean up my stock crank & rods too.

I'm looking to push some more horsepower, definitely not more than 400 - ideally somewhere around the 350 mark. I want to have good low end power, since its going in a long bed pickup - and want to make sure I maintain enough vacuum to run my power brakes.

Some info about the motor as it sits - 1995 350 TBI motor out of a van (this is about all the info I have, my Grandpa put the motor in the truck 15 years ago). I've currently got a Weiand Street Warrior intake manifold (will need to be replaced with new heads) and a Edelbrock 600 (or 650, I'm not totally sure at the moment) CFM carb.

My machinist is going to order the pistons, bearings, etc. just to make sure everything matches up - and I mentioned that I'd like to bring the compression up while still using pump gas, so probably around 9.5:1 or so (per what the machinist said)

Here's where I get lost and have read so much conflicting information I figured I'd just ask around on here.

I'm looking at getting some aftermarket heads - was eyeing the Brodix IK180s (64cc chamber, 180cc intake runner, 2.02" intake valve, 1.60" exhaust valve) anyone have experience with these? Would they be adequate for my HP goals?

I also have ZERO clue about camshafts - I have been researching for days and am just not sure - was probably going to go ahead and call COMP to get their thoughts. The heads are my main concern, since I want to get them ordered so I can drop them off at the same time as my block, just so the machinist can check them over.

Appreciate any advice!

Click to expand...

Depends on what you are going to use it for and what kind of power you want. I first would think about the differential gearing. Your truck is not light, so I would stay away from super-tall gearing. It may increase mileage out on the open road, but it hurts acceleration. If you have a standard transmission and 15 inch wheels, I would use 3:54 gearing. If you have an automatic, 3:08 or 3:23 work well. Now for the engine, I would use no hotter than an R/V cam if you will be using it for a a daily driver. A semi or 3/4 race cam would take away low-end torque and considerably increase fuel consumption, and, if you are in a smog-check state, make it impossible to pass, as aggressive cams need a very rich idle mixture, which means dirty exhaust. You also would need to gear down, maybe 3:73 or 4:10 for standard trans, 3:40 for automatic, which would have your engine revving pretty high on the freeway. You would also have poor vacuum at idle. Hope this helps.

J. B.