After doing research on heads, pistons, cams, and crankshafts, I wanted to ask you guys for your recommendations. My goal would be to make around 300-400 horsepower with a max budget of 4k. 1976, 350sbc, TH350. A completely stock car.

To start, the carburetor that I am currently running is just the stock Q-jet with a stock intake. The Carb has been rebuilt by lars and does good for what it is. Could I keep the Q-jet intake/carb and will it be fine with a 250-400 hp build? Or do you guys recommend a different carb/intake setup?

Next, would be the heads, I currently have the stock heads. I have read that Vortec heads are the way to go but I haven't been able to figure out which ones will fit 76 sbc. Are there any other heads that you guys recommend that would go with a cam of your recommendations?

Next, would be the cam, honestly to there are so many cams that I could choose from. For the cam, I just want to know what you would personally run, this will be a cruiser/ street car. Nothing crazy, mostly something with good low-end torque would be preferable.

After that, headers/ exhaust. What headers would be the best for the vortex heads or just what some good headers to run for that 300-400 hp goal. I would rather not run side pipes but an exhaust that runs to the back of the car. Another question with exhaust, is I do have access to a decent welder. Would it be worth trying to fabricate my own exhaust or should I just buy a set that goes to the headers?

Next, the internals. Would I need to change from the dished pistons to something else? Or could I stay with the crank and pistons?

Lastly, would be the transmission. What do you guys recommend? The TH350 does sit high in rpms when cruising and would that be okay with a cruiser that has 300-400 power?

I know this it alot, but really literally anything will help. This will be my first time building a motor, if you have questions for me I will try and answer them. I hope I gave you guys all the info you need to help me with this.

Thank you for everything!

 

IMHO Desktop Dyno is the best investment you can make to figure out a good combo. Asking here what cam/head I should use is like asking 10 people on a sunny day "is it sunny out" and you'll get 10 different answers. Just my .02 cents.

 

Maybe 3x your budget. One thing leads to the something else. There are several folks here that can keep your focused on your goal and spend. Your list will things you want to do will be shorter.

 

Welcome to the forum, And some of the best looking cars on the planet.
Building an engine is a huge undertaking, It is better to have someone you trust to coach you along.
At 19 yr old I admire your enthusiasm. Not a one of my 4 boys had that kind of interest to dive in that deep. But a few of my students did.

I'll give you a build recipe, step by step. First thing you need to know is your 76 was rated in net HP, and almost all engine builders, etc, talk gross HP.
1971 was the only year GM rated them both ways. A basic 350 L48 was rated at both 210 net HP and 270 Gross HP.

The good news is your 180 HP engine (net) is very similar to that engine and is only 30 weaker. So yours is really 240 Gross HP right now.
The main difference in those 2 engines is your single exhaust and catalytic convertor. If you can legally put true duals on it, you basically get the 30 HP back. The exhaust helps a lot, I did that on my 75. Headers will help some more. Turbo mufflers too. So now 290 HP already (gross) That is your biggest bang for the buck. Better heads definately help a lot, like the Vortecs, maybe 25 HP, so 315 HP now, A camshaft change would help some, but you want power at like 1200 to 5200 rpm for a cruiser, so it's not much bigger than you have now. Say a 212-215 dur @ .050 type cam. (The old 300HP cam is only 195). Keep the cam mild. 330 HP now. The Q-Jet carb is a really good carb, when un-molested. If it runs well, keep it, But a better Q-Jet style intake might add another 10-15 HP. So 345 now. You haven't even spent much money yet. But now you have the foundation to make it stronger. If you want to change the pistons the block needs to go to a machine shop. Hyperuectic pistons are fine for your use, but upping the CR from 8.5 to like 10:1 will really make it feel crisper, and help MPG. Might be worth 10-15 HP. So now you around 360HP with a real strong low to mid rpm TQ monster. Perfect for the street and cruising. More cam gives you more rpm, and you may not want that. The engine takes longer to wake up, say 1500-1800 to 2000 rpm, that's too much for what you are describing. More expensive, new aftermarket heads would help even more. They make the biggest difference. You could add another 20-30? with some really good heads. Say 385HP now. That's 60% more power than you have now, with similar driveability & manners, It would be a rocket!

Have fun and make it yours!

 

I find that an interesting answer, (above).
And I know Leigh is knowledgeable.
upping the compression with some flat top hyper pistons would definitely help, and I believe compression makes power. More than the conservative estimate above.
Trip to the machine shop?? I don't know, I honed my cylinders with my engine still in my car.
Yes I own really nice Sunnin block hones.
just about any aftermarket aluminium heads will be better still than the vortex heads.
a truly properly recurved distributor is worth it's weight.
Cam??? 268H.
Intake??? No recommendations. Don't know your clearance requirements.
Your carb? If staying with a carb you can't do any better.
Headers, true duals. Very best bang for your buck.
Me, I don't run mufflers, just cambered exhaust.
good luck young man! Buy tools instead of paying someone to do things for you. I have tools I bought when I was 12. And still use them to this day.
Oh, and I'm old now. Well by your standards. I'm in my mid 60's

 

So you want a tq engine with modest hp 400hp. Get a scat rotating assembly for a 383 build, shoot for 10.0 compression, any modern head will get you those hp numbers. A cam no more then 220. At 0.50 with a wide lsa 112. This will give good idle vacuum and a wider power band. You do not need forged Pistons or a 4340 steel crank for this rpm level. One of the cheaper scat rotating assembly will do the job. your QJ carb more then up for the job your intake will do it to. We're talking 400 hp out of 383cu. Barely over 1hp per cube.

 

Save your block if it’s numbers matching, put in a crate long block 383 with a roller cam. You will save time and money in the long run.

 

Leigh does a good job describing different levels.......
Does the engine run good right now? Just add a better intake, cam, headers, a proper timing curve and true dual exhaust......this will put you in the 330hp range.....that's 260-270 to the tire....that is a 14 second car......see how you like that and if you want more, then bolt a pair of heads on it......
Building 400hp now is almost too easy.......
Vortec heads to me are more hassle than they are worth and I like to stick to heads with the old style intake and exhaust flange......

Jebby

 

Purchasing a long block or crate engine will be challenge unless you have a loading dock, forklift, and a way of moving 400+ lbs.
In fact, the first thing the shipper will ask is, do you have a way to unload it off his semi?

Having said that, take a look around on Summit. They have short-blocks that two or three guys can unload off a truck.
Look for short-blocks with the pistons that will meet your needs while keeping in mind the chamber you intend to use on the heads later.
Four bolt mains maybe?
Without cam & timing chain?

With all the block machining done, bearings clearance checked, pistons in their holes, the rest of the build is easy and rewarding.
Then at a later time order aluminum heads, cam, timing chain, headers, IGN, Intake / carb, etc after a thorough research on best bang for the buck.

 

As the others said, heads and exhaust are where the big HP is at.
Put some really good AFR heads on it, (small ones) (or Edelbrock or even cheaper promax) and you may find you do not even need to touch the short block, if it is still sound.
Buy a leak down tester and test it to be sure the ring seal is good. Then decide.
The compression does not buy you all that much HP at this level, but it sure feels better than what the numbers say!
So if the short block is good don't even touch it. Spend the money on the heads instead.

Engine building is a subject where you will get 100's of widely varying opinions, so listen wisely, and listen for the consensus or the common threads.

I have worked with my best friend on parts selections on 100's of different engine combos, but he did the building & the machine shop work for 5,000 engines. He was the real builder, but is not with us any longer. There are some things I absorbed from him from a machine shop / speed shop perspective but much I do not know about the actual assembly process. Jebby (above) has built and tuned 100s of engines himself. He is much more knowledgeable than I on building & tuning. So his input is extremely valuable and I am glad he basically agrees with my write-up. There are some other very knowledgeable builders on here as well.

It can be really fun if you enjoy it! Just try not to get confused.

 

I'm old also, I 2nd the buy your own tools, they are much more expensive today, have any friends in the automotive repair industry
While I bought tools, I didn't at 12, But I still have many that have been with me 50 plus years.
Buy a good quality compression gauge
Buy a good quality leak down tester = do you have an air compressor

Find out the condition of your motor now before diving into the money pit

report back with your results & others more familiar can help you.

 

Not bad advice.....as if your engine checks out ok there is no real sense of rebuilding it.........unless you just want to.....

Jebby

 

I would have to ask, what is your experience level? Have you rebuilt any engine before, if so what? What kind of mechanical experience have you had thus far? Brake jobs, body work rebuilding or fixing various car components, motorcycles, lawnmowers etc? Do you have more than a socket set and some screwdrivers for tools?

It's easy to get in over your head if you just blindly jump in.
All the numerous details and steps involved in rebuilding an engine is taken for granted by those that do it and know how to do it. They have all the tools and know all the intricate details by heart. They don't really know how much they know until they try to teach it to someone.

It's hard to talk shop if we don't know the experience level of our audience.

 

Hello everyone and thank you for all the info so far!

As of right now, I would say my experience level is ok. I have done my brake lines, mc, booster. Dropped the fuel tank, fixed leaking rubber lines, new parking brake shoes/accessories, have took off the intake and painted it while the carb was being rebuilt. I have replaced the radiator(pain in the A**), fixed the seatbelts, replaced manifolds, and Im sure Im forgetting somethings. Just when it comes to motors and how to build them, I don't really have anyone on speed dial. I've taught mostly everything myself through my own mistakes. I have some but not much experience on how to build them, I personally believe I can do most with out any trouble, its more making sure everything works together.

The motor does leak a lot, and yes I do know that I can replace all the seals with the motor still in the car but in the current state its in and winter apporaching I want to pull it. i went ahead and did a compression test and all were within 10-15% of eachother, one of the biggest problem's the car has is it likes to burn oil. Taking my spark plus out I notice oil on the threads making me believe that the valve seals are going out. I want to replace the seals and I see as of those "I am already here" situations and with the rocker arms/springs/etc out it feels like a good idea to go with a cam kit that has springs and so on.

Some few questions, what is leak down tester? and what is recurving a distributor? How can I do it?

Another question is if I were to go with AFR heads where can I find headers that wont give me fitment issues?

After reading what Leigh said, I believe the plan is to go with headers, intake, heads and a cam. (Plan on sticking with the QJ) This I believe will make me happy enough but also not break the bank.

If you guys have any more advice or questions please ask! Thank you guys for everything so far!

 

Does it blow smoke? If so, when? Upon a cold start? When accelerating? Or when you get the revs up and then let off the gas completely and the engine brakes itself down?

 

I bought a set of Vortec heads off FM, and I'm going to see if I can do something similar to what you proposed in your first post with a surplus engine.

However, after taking an LS mostly apart to do a light rebuild, and after pushing it around my garage next to the surplus L48 it replaces, I'm really reluctant to ever touch an SBC again.

Right now, near you on FM or Craigslist, there are probably a dozen Yukons, Tahoes, and GMT800s for sale, complete and running with an 4L60e, for half of your engine budget. And probably a dozen more 5.3L LS-based engines for sale for a quarter of your budget.

What's better about that?

• No coolant in the intake manifold
• No exhaust passage in the intake manifold
• No carb
• No distributor
• No mechanical fuel pump
• Better heads and better flow
• 4-speed automatic

So, should you rebuild your (I'm assuming L48) and leave it attached to that TH-350? Sure. Probably. It's a great learning experience. Or, for the same amount of wasted brain cells, a bit more time, and possibly less money (if you don't do it the way I'm doing it), you could have an LS-swapped C3 with overdrive.

It's your car, do what's right for you. Understand what you are willing to learn, buy tools for, and accomplish in the garage space you have.

 

I think a LS would be better.
trouble with vortec, good heads, is intake mani and heads accessory holes.
too many "have to make do" with limited intake manis etc.
shame really.

many have been where you are.

 

We have all been where this young man is now.
At this point in my life I have truly forgotten how many engines I have rebuilt. Had one come in to the shop 2 days ago. Apparently I completely rebuilt this customers engine from the crank up. Our new service manager asks me if I remember it. Even after repairing the issue, (a broken spring in a cam chain tensioner causing a rattle). I still don't remember it.
But my point is. Once upon a time. I dove into my very first engine rebuild. We all did.
only one way to learn. Throw the young man in the deep end. Some of us swim. Some drown

Only one way to know.
Buy tools. Do it yourself, only YOU love your car as much as you do!
Make mistakes,
OK.
Learning curve.
Move forward, learn from those mistakes. Keep going!
The immense pride from doing it yourself will truly be worth it in the end!

 

A leak down tester will tell you if you have leakage past the rings, or the valves, or both. So you get a pretty good idea of how good idea of the piston to bore ring seal / long block condition is. But you do need an air compressor.


Good luck! Do not be afraid to ask questions or make mistakes. Unfortunately we all have had to do things twice sometimes to get it right, and still do!

 

An LS swap will need some light fabrication but if you're comfortable with that it should be considered. You can get a good used Vortec truck motor for pretty cheap. It will have the heads you first mentioned, but you'll need a Vortec dedicated manifold to run with your carb/distributor. Plus you get a serpentine accessory drive with it. Simply pull the Vortec distributor and put your present one in, with a melonized gear. No fuel system mods, power steering changes, possible oil pan, motor mount adapters, etc. Do your research first.