360 year differences

340mopar said

The later 360 head does have the ports that's why the exhaust doesn't flow as well as the "J" head unmodified. I am obviously having trouble explaining it so I think I will just retrack what I said on everything.

Cudakyle disregard my posts.

Thanks,
Chuck

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Chuck,

I see what your getting at and I should have been more clear. What I meant was that I have '74 "J Style" heads that are original to the truck but they do not have the air injection ports. I have the casting number written down somewhere just not here. Am I wrong in my assumption that the air injection heads did not show up in production until '75? :-|