302 casting on a set of 318 heads
The O/D would drop the RPMs some more, but I am still wondering the RPM difference between that one and an A904 lockup. I will ask the guy you mentioned. We will be running 3.73s in the *** end, so an O/D might be better. Pros and cons though. A904 is straight bolt in. A500 i have to mod the crossmember.