The combo is a 1990 Dakota street truck(approx 3550-3600lbs with driver),3.73's,stockish 727, PTC 9.5" converter that flashed 3800 with the former stock lower end 360 magnum, 750HP holley, 1 5/8" Hooker headers,Edelbrock RPM intake. The new shortblock is 408" with 10.2 to 1 comp, hyd roller 237/245 .585 108lsa in @ 105,Same Magnum R/T heads 2.02/1.6 no flow bench help ,valve springs are 170/395open doubles. Other than increased cubes,slight comp increase,10ish degrees more duration and slight lift(area increase)it's the same as it has been for years. LOL any guesses? Should know some answers Friday nite so.......Why not take a shot??