What should I do??

[pokertramp]

The engine I have is from a 1975 chevy truck, 350 4 bolt main. I did the valve cover gaskets and the head numbers I came up with where:

Driver side, which I could have read wrong: 458642

Passenger side: 468642.

So I have not seen much on the 458642 but for the Passenger side I am getting 75cc heads, 1.72 intake, 1.50 exhaust.

What is my next step in this? The car seems like it has great power right now,has full length headers, performer intake and edelbrock carb. I am not sure if an aftermarket cam is in there or not.

How much HP do you estimate I have right now?
What do you estimate I can get with a cam swap, heads, intake and carb?

 

[custom442]

umm, I don't think you'd find two different casting numbers. Better double check the one you read wrong

Is the engine stock now? Stock those engines were around 160 hp to 200 hp if you were lucky. With your additions, maybe 180-220 hp. But you've left out a lot of variables. Remember you have a smog block 350, not the best starting point but it can be built. I would personally save up for some nice aluminum heads, patriot, world products, edelbrock. Even GM has some nice fast burn heads.

Which edelbrock carb is on it now? ...The performer can't be upgraded much, it's a fine manifold for low end power and good vacuum. A new cam would also be a good idea, but if you're getting heads I suggest to get those first and match the rest of your bolt ons.

 

[axisg]

keep your eyes peeled for a mid to late 90's truck motor.

- roller block
- better heads
- 200+ HP to start ( most are closer to 300 hp stock )

That way you are an electric in-line fuel pump and a better cam from 300+ hp

 

[maliburacinfreak]

with those junk heads thats probably a 140hp motor. common for that era.

 

[SafariWagon]

A 75' block isn't a bad block. Usually if they came painted orange they are thicker castings than the blue painted blocks. That's a general rule of thumb. Keep what you have but upgrade the heads. This is where you should spend the majority of your money. An engine is an air pump. If it can't breath than there will be no power. I would also reccomend alumninum patriots. I have a BB chevy with a solid flat tappet cam making 601HP and 601 FT LBS of torques with those heads.

 

[DRIVEN]

I'm with axisg. Look for a roller block 5.7. The motor you have is a truck based application. Those heads are a small valve, small port, low compression design. They were made to pull/carry loads. That means torque was the concern - not high RPM horsepower. I think the combination should be left as is. You won't really be able to improve on it without a head/cam swap. Just enjoy it.