i just got a rebuilt 355.. i have a set of heads that have just come back from the shop that i was going to use on my 305.. the heads are 416's and i had 1.94 and 1.60 valves put in, as well as a mild port job. the heads are 58cc's

can i use these on my new 355? i really dont want to buy new ones.

also is a 93LT1 cam better than the stocker? i have one , and the engine is still on the stand, so i didnt know if i should change it out or not.. thanks guys

 

It depends on what pistons the 355 has. If they are flat tops w/valve reliefs it would be almost 11.0-1. If they are dished like stock it will be a little over 10.0-1 and that would be pushing it to the limit. 91 octane would not be enough with steel heads.
Yeah, the cam is better than an L03 or L98.

 

yeah the pistons are flat tops with the valve releifs.

DAMN IT!!

k so it looks like i need to get some L98 heads then? what is the CC i need to be looking for?

does using a thicker head gasket make any difference? i really wanted to use these heads(416;s) but it looks like i wont be able to then, right Don?

 

It would not be a good idea.
You need 64cc heads and a .051 gasket to keep it at 9.8.-1.
I would use the GMpart #12557236

 

i dont suppose you have a set of heads that are ready to go, do you Don?

 

What about 416's on a 79 LM1 350 that had 8.2:1 cr stock? What would the cr be?

 

LM1s use 76cc heads ...

I would recommend that you use 4.00" bore heads with any 4.00" bore based engine. Too many hidden problems from just slapping on 305 heads on a 350 engine.

 

That would be around 9.8-1....barely make it on 91 octane

 

are there any casting #'s i should avoid? i found a company that has 64cc heads for a 350... what #'s should they be?

 

#1083's are L98 '87-'92 for camaro.
#191-193's are L05 350 for trucks.

 

well its a good thing i asked.... the shop said the heads were 193's

im just going to say screw it... and buy vortec heads from Jegs. yeah i know... gotta change the intake as well..

does Scoggin Dicky have 87TPI manifold in vortec style?

 

k screw that idea... im not spending over 400$ on a damn intake..



anyone have L98 heads please?

 

Dave...
I found you a set of heads...let me know if you still need them.
PM me.
Don>>>

 

thanks Don, but i just scored a set from a list member on saturday... Thanks Fernando!!