Alright,
So I have a 468 in a 90 454 SS truck. I built the motor to be used as my "work truck", and gas was $4 a gallon. Problem is it falls off at 4500 RPMs, flat on it's face. I thought it was springs, so I swapped from worked Peanut ports to 70 LS-5 heads w/2.19 intake valves, plus port/polish. Lost my bottom end, and ran same ETs, 9.0s 1/8th mile, 2.0 60' w/sticky tires. Motor has 1.50 dome TRW forged pistons, stock bottom end, 4 bolt mains, aluminum roller rockers, old Holley single plane intake, Holley 750 vac secondary carb, Holley Blue fuel pump at 6 psi, HEI w/accel module, coil, and wires.
Here's the issue-When I built the motor I installed the Edelbrock Performer plus cam, 5.00 lift, 115 lobe seperation. Cam said Idle to 5500 RPM powerband and 480 ft lb of torque. I had a buddy power tune it, and it pings bad at anything over 12 degrees initial advance when warmed up with stock advance springs on Premium fuel.
What cam can I use that would fix my low HP and RPM issue without wiping out my 10 MPG? I still want vacuum and will run my AC. What HP am I at now?
Truck has a turbo 400, shift kit, gear vendors OD and 3.73s. 2000? stall.
Thanks for any responses.