OK, I've got my BB 402 back from the engine shop. It's been mag'ed and hot tanked, new frost plugs and cam bearings, all honing is done and block is painted. We're about ready to start reassembly with the stock crank and pistons. I'm looking to finish this project with about 425 horsepower on pump gas with about 9:1 compression. It's a package goin in a 1979 Vette (3600lbs) with a TH-350 transmission and a TCI street-fighter convertor (3200 stall roughly).

I do plan to street this car/engine combo however I am looking to improve my drag racing times as well. I also run an MSD-6AL with a 3 Step and a recurved GM distributor. I also have had great luck running the Quadrajet Carb(thanks Lars).

Those are the things that are official. Now I have a few decisions that must be made soon. I'm planning to order a set of oval port Edelbrock Performer RPm heads, and then likely also a Performer RPM intake. Exhaust will likely flow through some smaller tube headers (under 2 inch).

My question is does any of this sound logical? Now please note I know the most important item in this whole combo is gonna be the cam selection. Does anyone have any advice to help me get this combo completed.

My car has run 13.9's with its original L-48 so I'm lookin to bump myself into another class here. But I'm also concerned about having a good street and strip package.

If ya have any advice for me, I'd love to hear it.

Thanks

Indynut

 

That makes sense to me. A long time ago, I put together a 454 for torque. I used cast iron oval port heads, an Edelbrock, C396 dual plane intake and the smallest tube headers I could find for a big block, 1 7/8ths", I think. My factory A/C, SS 396 Chevelle ran a best of 12.21 @ 111 mph in the 1/4. I had a B&M Hole Shot converter (1800 rpm stall?) with 4.11 gears. With slicks, the front tires would show just a little bit of daylight underneath them when I launched. This was all with 30 year old technology.

Especially since you are using aluminum heads, I would pump up the compression to 10.5, minimum. I had about 11-11.5 with iron heads. The cam was a garden variety TRW flat tappet hydraulic. I don't remember the specs, but I could see if I could find them, if need be. It wasn't anything special and it idled fairly smoothly at 700 rpms, in drive.

RACE ON!!!

 

Sounds like you're thinking along the right lines. The 396/402 is basically a heavy small block, so you need to think along those lines.

When you say stock pistons...which ones are they? Are they std bore with small dome.The 10.25 types? Are they original GM ones or are they aftermarket replacements. The reason I ask is that the replacement types are generally shorter and the deck height is often a littel low cutting compression.

I think I would do whatever is necessary to get it up to an honest 10.5 compression at least, especially with aluminum heads. 9.0 is way too low to get the power you want and to have it be real responsive. To get power out there it needs some decent cam, so compression will need to be up there to handle it.

To get decent compression with stock pistons you're going to need heads with chambers down in the 100cc range at the most dependingon deck height and gaskets. You can get the Edelbrocks in that size..they used to be called the EFI versions.

But I would seriously look at the Brodix Race Rites. They have flow numbers that are much better.

Are you determined to use aluminum heads? The reason I'm asking is this...is the 396 an interim engine where eventually you will move up to a 454, 496, 540 or whatever? That could help determine heads.

A good ported set of iron GM oval ports could provide the power you want for less money. Not sure if the 396 is where I would spend the $$ for aluminum heads unless I was going to go larger later.

A new set of pistons with larger domes and a set of ported 049 oval ports could make decent power.

You're good on the intake choice..the RPM's and air gaps do well. Headers should be 1-3/4" most likely...maybe 1-7/8" ones if cam is good sized.

I always like solid cams, so I would do some digging for a solid flat tappet. You have a pretty loose converter there so I assume you don't mind getting out in the 6000-6500 rpm range? I have a couple of Crane's that I like that always work well. There are more aggressive out there, but they don't hurt parts and will rev all day long. You're going to need ot be up near .600 lift and other specs will be determined by the other manners you want.

What gears?


JIM