Ok, got a typical small block Chevy, had the "puff" at startup, compression shows good and even, so I'm thinkin' valve seals, since it had set around for awhile. Got to the part where you adjust the lifters, pushrod rolls finger tight ect. Book says to crank it down a full turn after that. Trouble is, after about a 1/4 turn the valve starts to open????!!!!>>>""?? I'm using the compressor method to hold the valve up while working, and you can hear the air start to seep out......Whats up with that?????????