Hi guys i am going to drop a 350 in my 87 iroc...i removed the heads that came with this motor to put my lb9 heads on it...but i had a question what head gaskets do i get since the block is the 3970010 block i dunno exactly what it came out of so i dunno which head gaskets to buy..thanks sorry for the dumb question...

 

So possibly just a set of 350 head gaskets should do the trick?? cause i just fitted the ones that where on the 305 and they where too short.

 

Before choosing gaskets, first get a straightedge and some feeler gauges, and determine how far your pistons are above or below the decks at top dead center. Gaskets are available in thicknesses from 0.015" to over 0.070", and your goal is to have the heads about 0.040"-0.045" from the pistons.

 

If you're talking about brand/type, I say go with Cometic gaskets. They are the shizz. As long as you don't blow them out, you can re-use them should you ever have to remove the heads.

 

How exactly would i do this..as this is my first 350 swap so im kind of new to this stuff. thanks

 

Ok, I have a knowledge bump question now. Why are you putting LB9 heads on instead of using 58cc heads? Won't this severely cut down on the movement of airflow through the engine?

 

I thought the 1081 heads where 58cc??

 

I think the other person meant 58cc aftermarket heads. But 081s are around 55cc stock.

 

First put the straightedge on the deck, across a cylinder, and turn the crank, watching to see if the piston actually touches the straightedge.
Forgot to mention, you'll need a degree wheel. And it's easy to look up the instructions for finding TDC. It can be done without buying a dial indicator.
Anyway, put the piston at TDC, and if it's touching your straightedge, then let the straightedge rest on the piston, and use your feeler gauges between the straightedge and the deck.
If the piston is below the deck, It could be as much as 0.050" down. Sad, but possible.
Get started and it'll become obvious. It's one of those things.

 

I believe the L98 Corvette with a 350 TPI Uses 58cc factory heads

 

Yeah, they're nominally 58, but due to production tolerance, one head could average 57c, and the very next one could average 59cc. So, a 57cc head, with a light clean up resurfacing of just 0.006" is 56cc. If you have 59, then mill it 0.018" to get to 56. Come on, guys, think it through. Whatever the head is reported to be, subtract 2cc to be safe. If it's 40 years old, it's probably been rebuilt a couple of times, so subtract another 2cc. Better to have your real SCR be 0.25:1 less than you think, than to have it wrong the other way.