qdre98

i have a 4.8 liter with a fab intake, shorty headers, stage two cam and ported heads. i have a 4l80e and a 3000 stall circle d converter but my car is wayyyy to slow anything will gap it unless im going around 50 which is where my down shifts line up but either way i know i make the most power in higher rpms it just takes so long to get there. i know its something wrong with my gearing or drivetrain cause the 4l60 i had on it before made the car have way more power off the line i have 273-308 gears(not sure but it is in that range) but i just bought 3.90 gears hopefully that'll make it gain that power back. let me know what you think the issue is. bro a 335i gapped me its a 1967 gto so the weights around 3400-3700

Y2K_Frenzy

The 60 has steeper gears than the 80 so maybe that’s where you lost a step.

Full Power

I have a 4.8 liter in a heavy pig....... 4.56 gears helped a lot.
11 pounds of manifold pressure helps too.
Let that short stroke motor SPIN !!
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"It all comes down to Traction, GEARING and Manifold Pressure."

SlowTBSS

The swap from 60E to 80E makes it a dog. TBSS guys deal with this when swapping to an 80E, especially when not making much power.

jetech

Not only are the gear ratios hurting your combo. The 4l80e takes more hp to turn. Your rear gears are awful. 390's will help a lot. Put the 4l60 back in

DualQuadDave

iTrader: (6)

The fab intake is hurting you too. A stock TBSS intake would be much faster and tons more torque throughout the range. It's ugly, but it works. Post your cam specs, I bet that's its touch too much, too. When your are building the little motors, the details matter more.

LilJayV10

iTrader: (39)

Add about 20lbs of boost. Problem sovled.