I have a 1965 425 engine and i have 1968 455 C heads will the c heads bolt right on the 425 without any problems???

 

If the 425 has a 45 degree lifter bank angle you may have pushrod interferance problems. The heads bolt up fine only the pushrods may rub the head where they go thru the heads when you try and bolt up the rocker arms with pushrods sitting in the lifters. 3/8 pushrods will certainly hit but I am not sure about the 5/16 pushrods. 65 and 66 425 blocks with exception of the Toro 425 had the 45 degree angle while the 455 and most 67 425's have the 39 degree cam angle.

 

C heads were used on the 1967 425, so they will physically bolt up. The issue will be the pushrod holes. Your 1965 block (it IS an A casting block, correct) has 45 deg lifter banks and the 1968 heads are drilled for 39 deg lifter banks. You will need to enlarge the pushrod holes.

 

Beat me by ONE minute!

 

Well that sux Ill just call the local machine shop and see what that will cost heck i already got 400 bucks in the c heads alone

 

It is not a problem that cant be fixed. I encountered this problem many years ago and ended up using 5/16 pushrods and possibly a little grinding in the pushrod holes and all is fine but I did use stock valve train.