what would be the better head for a 455? Mine are a J,are they worth doing work to?

 

depends what your doing with it. do ya want to go fast? then no J heads arent your best bang for the buck. C heads generally are the head of choice,and still reasonably common. in fact i picked up a set at a swap meet a month or so ago for 40 bucks needing a re-build...if its not to be hot rodded than use the Js...

 

I agree with Leadfoot, if you want power consider using other heads. You can get power out of the J's but the dollars spent in the machine shop would be better spent on some older castings that can flow better with less work. The C's are reported to be the best casting for doing flow work to and were used from 1967-69. The B was 1966 only and is suppose to be the same potential as the C's but it was on an engine with a different angle on the pushrods to rocker arms. The E is 1970 and a decent head, the G and Ga are 1971 and 72 respectively. They're decent heads too and come with hardened valve seats, better for the unleaded fuel today. The J was 1973-76These all came with both small and large intake valves, but I don't know of anyway to tell without pulling the head off the motor and measuring the valve. I don't think there's any difference in the casting, just how large the port was cut out for the valves. The Ka was a marine head and also suppose to be a very good head, I believe they were all large valve heads. The D, F, H are W30 heads and harder to find than hensteeth, and way expensive when you do find them. The only one I didn't mention is the A head used in 1965 and I really don't know much about that one. If you decide your in the market for some different heads remember to post your city and state. Parts that heavy are nice to find local if you can. John