362 SBO build up (need sugestions)

[01GPGT]

ok so i am finaly building up the olds 350 that was going to go into my long gone 1982 Grand Prix Diesel with a 78 350 swapped in

it is a 68 350 block that still has the standard bore and only .003 bore where. i am going to get it 0 decked and bored out .068 so i can use standared chevy 400 small block pistons i will still have enough to bore it out to a .030 over 400 piston if need be and still have enough wall

crank is a nodular cast crank from a '76 350 getting the rod jurnuals ground to accept SBC rods going to use a 6.2" long H-beam to keep the piston close to the deck. also goign to keep the stock stroke the crank should be fine as i only plan to spin it to 6500 any thing higher and i would just try to find a 330 crank (almost impossible here)

i have a performer RPM intake that came off the the '78 engine that was in the GP


now where i need sugestions. i can not machine any thing untill i have pistons and rods but i do not know what pistons i need untill i get heads. so would hogged out 307 5A heads be worth it? there the only ones i can find in the local junk yards hear that and 403 heads. out of the two witch would be the most worth it? want to get the engine close as i can to 10.25:1 compretion ratio. the 307 heads would be easier to get there then trying to use 403 83cc chamber heads :?

 

[monte olrac]

307 heads will kill your motors performance, That i do know, but you should look at some performance olds sites to see what options you have out there for heads, I would hate to see a good engine go to hell because of a bad set off heads

 

[joe_padavano]

You're building this killer motor, and you're limiting yourself only to heads you can easily find in a wrecking yard????

Check ebay or other Olds sites. #5, 6, and 7 heads are readily available for reasonable amounts of money. Get the W-31 sized valves installed in them (2.000/1.625).

 

[olds307 and 403]

Both heads suck for performance, even hogged out 307 heads would be lucky to see 200 cfm. 403 can flow but need a lot of work on the exhaust. Also huge 83+ CC chambers would require domes to get decent compression. Even #8 heads milled might fit the bill but early 350 heads are the way to go. Edelbrock RPM heads will out flow any of the heads but may need miling and an electric fuel pump. You will need a fuel pump upgrade anyways, much better chamber and have the RPM intake already. You will put near their cost with core price and refurbish.

 

[01GPGT]

i never even considered the RPMs but yeah your right for the price of buying a set of cast iron heads and porting them i could just get the RPMs and mill them a bit and port the RPM intake to match

i have been over thinking. on summitracing they are selling a pair of assembled heads for $1,035 thats a little over $500 a head no way i would of gotten a pair of ported cast iron for that