Okay guys, My tuner/buddy/ teacher and I are stumped. Previous set up
MSD atomic Air force
Stock LS2 Injectors
holley 102 DBC
4Inch CAI
LS7 MAF/ IAT
317 Heads
Patriot double Valve Springs
Manley Valves
LS2 head gasket
stock pushrods
ls7 lifters
long tubes
tr55's
3 inch exhaust
t56
4.10 Gears
Approx 9.5:1 compression
87 octane
LS swapped c10
The truck made 358Hp on mustang dyno
Story: Had a ticking lifter, tore the motor down ( bought used) to inspect. Found worn crank and rod bearings. Replaced them, found a failed lifter. Put a BTR stage 4 ls car cam. Measured pushrods (7.350? Cant remember but the engine builder measured for them) Shaved the 317 heads 60. LS9 Gaskets. New GM LS7 lifters. bumped compression to 10.5:1. Filled up with 93 Octane.
Made a dyno tune and a few pulls last night and it made 357.5 hp. How in the world is that possible. Same dyno, same everything. different cam, lifters, decked heads, new bearings, measure pushrods and new head gaskets. My tuner and I are dumbfounded. He's been in business since he stared tuning ( Grand national and fox body era) He's stupid smart but was busy last night. ( maybe we are missing something) The only difference I am seeing is last night my timing ran at 24 and the previous set up had timing set at 30.