I want to get new flywheel bolts,

they are 7/16's by 1 right?

what are the pressure plate bolt sizes? this is for a Manual tranny 455 by the way..

looked for the spec couldn't find it for sure.

I believe they are the same as a chevy big block but it has been so long! thanks in advance!

 

Depending on stock or aftermarket flywheel, they are 7/16 x 20 and can be .85, .875, or 1". If they are too long, they will hit the block. Yet you want them to engage every thread of the crank. Pressure plate bolts have long shoulders, 3/8 x 16 thread, 1" long. Mr. Gasket (#910) and others (e.g. Pioneer S-1120) have them. With a thin .34" thick flanged Cat flywheel, for example, the ARP 240-2801 bolt, .85" long, is good. The stock flywheel flange is .48" thick, and 1" long flywheel bolts work. Original equipment flywheel bolts were 59/64" long (.92")

 

Thank you sir!