My present engine is a 71 LS5 either out of an Impala or Monte. Est. about 425 to 450 HP. Flat top piston. Stock lower end. From the day I bought the car (2003) the engine had a light throttle rattle easy to hear only on a light pull and above 2000 rpm.. It did this with stock point Dist. at 8 degrees timing and MSD at 18 degrees, no change. Even after all new parts in heads including 1.19-1.88 valves, springs and port clean up . . I was told it was piston slap. Bothered the hell out of me to this day. But never a problem going to 6 grand wide open throttle runs. BUT, just recently the oil pressure made a big change. Starts up cold at approx. 68 to 70 psi as normal but after 20 seconds drops quickly to 40 and below and after awhile lucky to get to get 40 at 2000 rpm and above. Was ALWAYS in the 60's when giving the throttle.
Its TIME !!! Just sent my pro magnum roller rockers to Comp cams for rebuilding than on to MJ.
Been wanting this MJ engine for a few years now. Just been watching others with theres and questioning them for a few years. Everyone said the MJ engine was perfect.
Went with the 570 HP with upgrade Hyd roller.
Present engine coming out soon
