I picked up a rebuilt head recently. The head has been shaved more than once. (not exactly sure how many times) But, lets just say there is still plenty of space between the deck surface and the warning hole. The head was also built with oversized valves, 1mm on both the intake and exhaust. Now, this is going on my untouched stock block. What do you guys think I should do? Stock evo 8 headgasket or the thicker 9 gasket? I'm a little torn on this decision because 1) I don't want the larger valves to make contact with my pistons and/or 2) I don't want to unnecessarily raise my static compression by going with a thicker headgasket unless I have to. Any recommendations? Is there any measurements I can do to check if there will be contact? Thanks for any help.

EDIT: Using GSC s2's with the rebuilt head.

 

i would suggest stop the guess work.
work out how much material has been removed off the head, factor that in with the thicker Evo9 headgasket and make a calculated decision.

Personally i would go with the Evo 9 HG.

 

Is there a certain value I should reference? For example, if I measure from deck height to the top of the head?

 

Good question....i am doing a hg change now on my original head that has been milled once....hope it is just the hg. I have coolant on top of the #3 piston only and the car smoke like a chimney.....2.3 stroker with an fp red aem ems tuned on corn gas...using arp studs. I hear that these studs can be used more than once....how much truth is there to that I wonder

I know that evo blocks like to crack here but I would be shocked if this were the case...and you would think the coolant would escape through the crack and the car would not smoke...either way I am pissed cuz I just got finished freshening up the qm twin plates (evo trannies are a ***** with no lift)

 

if the evo 9 gasket is thicker but you have removed material from the head would it be relatively close to the same thing as running the evo 8 gasket on a non resurfaced head? i guess what im getting at is if you run the evo 9 gasket you might solve the clearance issue without changing static compression.

 

A thicker gasket will lower static compression ratio. I doubt the difference between and 8 and 9 gasket would be noticable. I would use a 9 gasket regardless if it is a decked head or not.

 

I would do this, but still try to get some measurements for the sake of knowing.

 

Gentleman, you are in luck because I am pulling my stock IX head this weekend due to 90psi in cylinder #3. I will try to take a very accurate measurement and post results.