My setup is as follows..
76 Corvette
LM4 5.3 aluminum block
T56
LS6 intake
1-3/4" LT headers
4.11gears
HP Tuners
GS392 fuel pump
Took the car to the dyno sunday(I will have the graphs in the next day or so) all 3 pulls made about the same 255whp. This setup should be making around 290-300whp. Didnt even read air/fuel up until 4500 rpm, running super lean. I knew something was up which is why I took it to the dyno. 1st gear just didnt have as much pull as I thought it should, just feels dead. Shift to 2nd and it pulls hard, mainly because it doesnt fall below 4500.
Are the ls6 injectors different from the 5.3? What could be the reason for running so lean? If anything I thought the setup would run rich at first. Im running the 5.3 maf by the way.