Need advice on building a 400+ Hp Chevy 350 race engine street / track

[AIKI77]

I bought a 68' C-10 about two years ago and it had a rebuilt 350 in it (not stock). It ran great and had good power ~300hp. To make a long story short I pulled the engine and sold the truck (rust bucket).

I bought an 86 S-10 Blazer with a 350 swap TH350 trans 3:73 rear end (stock), the engine in the blazer is about 350hp (at least). I owned a 2000 LS1 WS6 and this Blazer would put it to shame. The problem is the Blazer engine is due to be rebuilt. Its smokes real bad when I start it up (valves/valve seals), it also blows some black smoke when I get on it.

Right now this is my daily driver and I don't have enough time to rebuild it. I was going to do a quick swap with the engine I pulled from the c-10 but I noticed some idiot jacked it up by the oil pan. So at a minimum I was going to have to replace the pan. When I pulled the pan I was happy to see it was a four bolt main. I then pulled the heads and ran the numbers, its a 010 block bored .030 over with flat top forged Aluminum pistons. The heads were 1.92/1.50 non oval port (low compression heads), I was only going to inspect it and reassemble it until I found a ton of carbon build-up on the top of the pistons and on the valves. It was also leaking air around the valves when I was pressurizing the cylinders to compress the valve springs. It looks to me the valves were ground down to much when they rebuilt the engine. They may have just rebuilt the bottom end I dont know.

My question is what is the best way to get ~400 hp out of this engine by just replacing the heads, cam, distributor, intake and maybe the carb? I have a Edelbrock 650 CFM carb and a performer intake. I have been looking at some double hump heads (64cc 2.02/1.60) but dont know if this would be over kill. I have also been told to use Vortec heads. I am a jet engine mechanic by trade and am going to school now. If you have experiance building perfomance engines I would really appreciate your input. Thanks Paul

[MrPbody]

Paul,

A couple of things...

Small blocks nevert had "oval port" heads, that's a big block "term". "Double hump" 327 heads were obsolete in 1969. Vortec heads are actually quite good. A little exhaust seat/port work and they're VERY good. No need for 2.02s for the level of power you're after.

400 HP for a "driver" is doable, but with 355 CID (.030 over 350), it makes for a bit of a "rowdy" engine (cam lope, fuel and ignition issues). The "smart play" is to "stroke" the 350 to a 383. That is, use a 3.75" stroke crankshaft and appropriate pistons (pin location differs from the 350) in your 350 block. IMO, 383 is the BEST street/strip combo using SBC. Good low-speed performance and more torque. If you stick with the 5.7" rod, or better yet, go to a 6" rod, high-revving durability is also there.

There are many performance combinations for these engines. Define as close as you can, your exact requirements. Pump gas? Manual or auto trans? More driving than racing?

NOTE: A "race engine" is in a car (or truck) that "lives" on a trailer unless it's at the track. If it sees street time AT ALL, it's a "street" engine. Each have very different internal requirements.

Jim

[codythesamurai]

Forced induction dude!
Turbochargers, superchargers, or even a blower. Yes, you CAN run a turbo on a carburator.

[AIKI77]

Thanks Jim.

I would like to be able to run it on pump gas. It will have the TH350 auto in it now, but I will upgrade it to a 700R or TH400 when I get the money. I would love to stroke it to a 383 with a 400 crank but I cant afford to do that now. Plus it would be a waste of the current rebuild that was just put on the engine. I do however plan to do that to the engine I remove from the blazer.

I am just trying to get the most HP out of it I can buy just replacing heads, cam etc. (keeping it naturally aspirated). If I get 400 hp that would be great if not owe well I will just take what I can get. This engine. will be used more for short distance driving than racing.

Thanks.

[jru212]

The cheapest way is to add nitrous