I bought a set of j heads with the bigger valves.I was just wondering why people want more money for the x heads.Thanks for the info.I'm in the process of building a 340
I also just pulled a set of swirl port heads off a car my buddy was selling.he says you can build more compression with those heads is it true.Thanks for the info
I thought the X heads not only had bigger intake valves but they flowed better than the J heads. Not sure how they could have the same casting number as the J head. I currently have X heads on my 68 340 Barracuda.
You can buy stainless steel swirl polished nail head valves that bump compression up. I've actually have a 360 that I'm building for my 79 Aspen RT. J heads, 2.02.
They could have a variety of letters. I know of X, J, L, H,Y and W heads. The X disappears after they stopped producing 915 castings even though X heads came with other casting numbers.
i had 360 j heads on my 318 but when i did the motor work i put on 360 x heads 2.02 ,,anyone local want a free pair of 360 j heads ? needs new valves imo.i wont ship way to heavy can also have the oem rockers if ya want