What are the casting number on the top of those heads?
I haven't use the sidewinders heads so I don't know what they flow or how big the combustion chambers are confused
I have used and check a set of the newer(two or three years ago) set of 440 Source Stealth heads and they flowed way more than any stock Mopar BB head I have flowed and the combustion chambers where between 80.3 to 81.1 CC so they have smaller chambers than any of the early stock "516" close chamber heads I've checked and they flowed a lot more air work
My message is I wouldn't hesitate to use them on your Sons motor thumbs twocents

Last edited by Cab_Burge; 04/13/17 03:06 PM.
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)