it's got to be valves, the valves not closing, put air into the cyl. and see where it's coming out.if you hear air coming out of your exhaust pipe then its a exhaust valve, if you hear air coming out of the carb, then it's the intake valve. unless something went down the carb and is stuck or bent the intake valve my bet it's the exhaust valve.

http://s1055.photobucket.com/user/baldybenny/library/

1936 1.5 wrecker,1937 gmc coe,1939 Chevrolet coe,1942 4x4 coe, 1942 coe,1946 dump,1947 2 ton dump,another 1947 2 ton dump,1950 coe,1967 c30,1937 cat 22,1936 Chevrolet 5 window foremans coupe, 1914 ford speedster.