which would be better?
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Joined: Oct 2001
Posts: 236
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From: OK, USA
Car: '87 IROC-Z
Engine: Modded 305 TPI
Transmission: 700r4
which would be better?
Ok I have been told that it would cost close to the same to make a 300hp 305 and a 300hp 350. I was wondering if I slaped a TPI on top of either one which one would get better gas mileage? My bet would be the 305 but I'm not sure so any help would be nice.
Joined: Mar 2000
Posts: 43,187
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From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
I would say it would cost more to make a 300 HP 305.
These things are a little hard to predict without knowing details of the combination, but the 300 HP 350 TPI would probably get slightly better mileage than the 300 HP 305 TPI. The 350 version would have more torque, at a lower RPM, which is the main reason I say that. Certainly, you wouldn't need as much torque converter stall or gears to get the 350 version moving.
These things are a little hard to predict without knowing details of the combination, but the 300 HP 350 TPI would probably get slightly better mileage than the 300 HP 305 TPI. The 350 version would have more torque, at a lower RPM, which is the main reason I say that. Certainly, you wouldn't need as much torque converter stall or gears to get the 350 version moving.