after installing cat stage 1 cams on my jdm b16a (intake, header, exhaust, vafc, intake manifold) my car started running funny.. compression test came back 120 across. my friend noticed white smoking coming from my exhaust when you get on it.. and there's lots of black **** on my exhaust tip (did not do that before)

my friend tells me he seems to think it's a head gasket, what's everyone else think? hope i've been specific enough. for replys.