i have a 1987 Formula WS6 with the TPI 305 which i am ditching in favor of a 355 TPI which i plan to build myself. this will be my first engine and i could really use the following information. first of all and most important at this point, what are the codes for GM 350 blocks? i am going to look at a few so i need to know what the codes mean in general (i can't post what numbers on the blocks are as i don't know them, if i go with the numbers in hand i will know what not to pass up and the "right" block won't slip through my hands). also, what block would be the most desirable for this build? does it really matter? i know it needs to be a Chevy block to bolt the TPI up to, but thats about all i know. also, what pointers do you "pros" think would be helpful in building this, my first engine? thanks in advance!!!

 

run your numbers on www.mortec.com as for blocks if you want to keep the factory roller you need to look at only 87 and later. if you want all the strength out of the bottom end you can get find a 2 bolt and have a set of splayed main caps installed. the early 70 blocks are suspose to be higher nickle. if it were me i'd look for a post 87 block, the L98 vets were 4 bolt, other than that i think all others were 2 bolts. i seriousely doubt you'd need 4 bolt mains or splayed caps.

 

ok thanks, but what about the roller cam? i totally freakin forgot about it!!!! how will TPI perform w/o it? is there any way to put it in a pre 87 block? thanks again man!!!

 

You can put in a pre '87 350 block. You'll need:

Flat Hydro cam/lifters.

New flywheel/flexplate to accomodate the 2 piece rear main seal.

You might also need to recurve/retard the dist because if you reuse the heads, which isn't the worst thing to do, your compression is going to be high which will result in some detonation with the stock spark curve and timing.

I also recomend the spalyed main caps. It's added insurance. Get a 2 bolt block even if you go pre '87. They are much lighter, and if splayed can be just as stong on the bottom. The only thing you have to worry about after that is blowing out the top of the cylinder. That's a TON of power to do that. The old 4 bolts had a thicker deck and cylinder wall so they wouldn't flex as much at the top. Since they are heavier they make the front end sit lower which looks good, but has a tendency to bottom out on BIG bumps.

I would also go with a late model block because they are even lighter than the pre '87 two bolts. You can keep all of your original hardware. The roller cams also have faster ramp rates which results in better breathing without high lift or duration. Once again get it splayed while you are getting the walls cut and you should be OK up to the 450-500 horse range.

 

ok thanks ATO, i will keep all of that in mind.