Casting # is 39734874, and they're off my '71 350. Mortec has them listed as


3973487X...71-72...350..........75cc chamber


I was wondering if anyone had any more info on them. Thank you.

You might want to recheck that casting number...I think you got an extra "4" on the end of it. In any case, they are most likely the 1.94/1.50 valves version. One of the better heavy casting open chamber smallblock factory heads.

Hows that 4bbl install going?

3973487x 75cc 2.02/1.94 1.60/1.50 1698-73 Corvette LT1 350