prince

need help, have a 565 blown bbc, hurt spark plug on #2 cyl. ex. valve, install new valve, repaired seat,install new head gasket and milled head.,install new rings, piston look ok as well as cyl.wall. ran leakage test. 100 percent leakage on #2 cyl and 40lbs compression . no air was coming thru valves. #4 cyl was 80 percent with 60 lbs compression. block is oring and head has receiver groove. motor runs good 4.62@151. shows no blowby.other cyl. have 150 lbs compression. any ideas? thanks

zipper06

Sounds like you cracked the head or the block between #'s 2&4, i'm asumming you don't run water, but if you do you can do a pressure test with the plugs out and that will tell for sure if one or the other is cracked.

JMO

Zip.