Exhaust leak through carb????

Just ran compression test. All holes about 115 to 120 psi. 3 and 5 have about 5!!!! Low, compression 360, resurfaced heads and a flat deck on block according to machine shop that tanked it and cam bearinged it. Funny thing, it don't run hot, radiator hose don't get hard, oil is clean as can be and under hard throttle, seems to run fine. Just my luck
I just went thru the same problem. Turns out I had some stuck lifters. Wasn't letting #5 exhaust close all the way