I don't remember how big the injectors are, but i'm thinking you said 2 3/8 or 2 7/16" stacks. I'm gonna go out on a limb here and say the nozzles are also too small, if that's a V6 90* around or over 300"s I would definately have min. #16 nozzles, but would prefer #18's on that size bore. I also think that you have a problem with the pump, if it's not blowing by the HS set at 70lbs by the time you hit 5500/6000 rpm's it sounds weak. On the nozzles #12's are the high end for gas and the very lowest end for alcohol. We run 18's on any bore over 4" in a sm/blk and 16's on the 305 sprinter engines with 2 3/16" stacks. The barrel valve is real close @25%. A weak pump could also explain why it seems so rich on the bottom end and why it won't rpm on high end.
A car with that weight could easley run mid to low 6's in the 1/8 mi. with 1.30's 60' times.
JMO
Zip.