ok i have a 1991 305. its got a .465 .465 lift cam with full roller 1.6 rocker arms.... and for months it was runing fine.. then on monday i started up my car after school and it started nocking after 1500 rpm.. then today and yesterday.. it would backfire while worming up and still nock after 1500 rpm. i changed the plugs and checked the cap and roter and they look fine to me.. do you guys think it could be a bent valve. it didnt do that till after school it worked fine on the drive to school.

 

Well, are your heads prepped to handle that big of a cam? What valve springs are you running, and is that .465 the rating with 1.5's?

 

that is .465 with 1.5s so its like around .496 with 1.6s but i found out what was wrong it was a worn down tappet. it looks like a bowl in the middle and the cam is ok i took it out a looked it over and it is all good. so thanks anyways but i found the prob.