[Steves LX]

So I am going to pull my heads tonight. I am just curious if I see any evidence that I have P to V clearance how do I determine whether I need new heads or a new block. Both of mine have been cut on both the heads and the block. I really hate to have to replace the block ecspecially since I just had it freshened up back in January and have less than 2000 miles on it. I am still having all the sewing machine noise and I have replaced or eliminated everything else. So I figure I will pull the heads and see if I cant see any marks from the valves hitting the pistons. I had one guy tell me that I should be running quicker than a 14.10 in a quarter. He claims to have had a stock 302 foxbody and running 13.50's all day long with street tires. And I have mods done to mine. Mine has edelbrock 5.0 performer intake, F cam, 24# injectors, 255 holley FP, 75MM TB, 73MM MAF, aluminum drive shaft. I have yet to get a tune or chip for any of the mods yet though. So if he's running 13.50's bone stock and I am running 14's with mods than somethings not right. I personally think the car runs alright just that damn noise. I also just hooked up a nitrous kit with a 75 shot and I have ubeen using it here and there for the past couple days and other than the car chattering louder, as of now nothing has seemed any differen't knock on wood.
Also these are stock heads with stock steel rockers and crane beehive springs. and I have eliminated the possibility of the rockers hitting the retainers or springs.

[stang fanatic]

take a piece of clay (modeling clay) flatten it to 1/4" thick and lay it across the piston where the valves might touch (the flycuts if the pistons are flycut). install the cylinder head w/ a new gasket, and torque to spec. install solid lifters for the cylinder you are goping to ck with (you only need to do it on one cyl and you MUST use solid lifters). set you valve lash and turn the engine over 4 revolutions. removed cylinder head, carefully peel off clay and slice in half. (cut the horseshoe in two) measure the smallest portion of the clay...this is your clearance. around .060 for intake and .120 for exhaust is sufficient...anything less iss questionable. HINT...coat the top of the clay and the valve heads with oil to prevent sticking and irregular readings