douglange

Details-
'99 k1500 4WD Suburban Silverado
5.7L, 4L60e, 3.73 rear dif.
Location- Fairbanks, AK

The tranny finally gave it up after 148,800 miles, including 2 round trips on the Alaska highway pulling an overloaded 7,000 pound travel trailer and 6 kids in the past 3 years.

At what point in modifying the engine to gain more horsepower and realizing more torque, do I need to switch from a 4L60e to a 4L80e? It's not the fastest 1/4 mile that's important. It's keeping the cruising speed while towing an elephant uphill;-)

This is really a question of torque vs speed. It seems as though I need more torque pulling the trailer. But pulling is only occasional compared to regular street use. A 4L60e will give a little more speed, whereas a 4L80e will yield a little more torque. However, most pulling is in 3rd gear, so both trannys will pull the same with a 1.00 gear ratio in 3rd. If I rebuild the 4L60e, what would I need to do to increase the torque. Or is money better spent on the engine?

trever1t

iTrader: (14)

If you are going to pull often then at the least have a huge trans cooler but the 80e is the way to go.

performabuilt

iTrader: (24)

The 60e with a little more converter would be good and the 60e lower first is and advanatage when pulling

retraC

iTrader: (1)

Top Jimmy Performance in Palmer just did my 4L60E and it's amazing. He does great work at great prices and stands by all of his work.