Never quite got an answer on this..flat top pistons..head limitation?

Pokageek

Active Member
Jun 10, 2005
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MA, USA
Hi experts. I have very slight valve "reliefs" I think they are called, in my pistons. They are there but very small. Does this limit me on the heads I could choose from? I like Ford Racing gt40x because it seems to offer alot more exhaust than the Y AND b/c I just have a preference toward Ford parts. I know there's a lot of good aftermarket though..BUT I was wondering if there was some kind of limit on the heads I could use..This is definitely an area I am a beginner..but I learn fast. Thanks in advance!
 
Do you know what pistons you have? If so contact the manufacturer and see what size valve the reliefs were made for and their depth. With this a good cam grinder should be able to get the cam in the ball park as to whether or not it will fit, but if you have any once of doubt, you will need to check PTV clearance.
 
With a B cam and a 1.90" valve you should be OK unless you have pistons like those that came in the '86 mustang 5.0's. I'd imagine you can get away with a lot more than that though with an aftermarket piston.