I had them on my engine as well,383,6" Eagle rods,Scat 3.750 crank,SRP pistons 13-1,555" lift Howards flat-tappet 3/8th mile dirt track cam,950hp on alky with Dart Iron Eagle Platinum 215s with port work.Made 592 hp and 517tq,ran a best of 6.36 1/8th mile with 105.5 mph best and 1.30.1 60' best at 2800#.I got a deal on a set of Brodix -10s done by Rons porting service and put on the same engine and now needs a bigger cam to work with them,made 573hp and 513# tq. Also has 1.5 rockers and was with a 1.76 glide and 5.29 gear.