Well my drive train consist of a 4l80e and some 3.73 and 31.2" tires right now, since the 80e is being replaced for a newer 2005-06 model, Im swaping the gears in the rear end for some 4.88s and a trutrac, AS well as a bit bigger tire. 305-50-20 = 32" tire.

what do you guys think of this combo? The truck is my daily driver, but speed limit uphere is like 55mph max is 65mph. I have to deal with a lot of steep inclines and hills on a regular basis. Mostly stop and go, lights, and stop signs. I highly doubt I take it over 120 on the hwy here. So Im highly considering the 4.88 gears. My stall converter is a billet 3700 rpm, and If my 32s look smaller, I may go a bit bigger as well.

Just wanted to know what you guys think about that combo, Im sure it wakes the 80e up a bit more too. My goals is to have a really nice DD, and walk anyone from a dig or up to 120 or so.

 

If you run that combo compared to what you have now it would be close to driving around now in 3rd gear. At 2500 RPM's the 4.88 w/ 305/50/20's would be 3mph slower in OD compared to a 3.73 w/ 285/50/20's in 3rd. Drive around in 3rd and see what it is like.

 

Go for it

 

Well on the way back home, 40 miles hwy, I had it in 3rd gear from the time I left work. Not bad at all, seems to hover about 500-600 rpm higher than normal, also when I let off the go pedal the revs keep up higher than normal. 70mph was just shy of 3kprm. I think I was doing 60mph at 2.5k. I got to 80mph at 3100 rpm. Its really snappy In 3rd, and I think I likey.

What I like is that, now I can jump maybe 20mph without much change in rpm at all. I really think I may go that 4.88 gears. Just dont know what is the max top speed cruise rpm. I may also swap a cam in to increase my mid to top end power as well. As the engine will prob be between 2400+ rpm most of the time.

My current 80e (bought it bad) is slipping in reverse, and sometimes in 4th, it will kick out of OD and raise rpm about 4-500mph. If I drive it over 60mph. As I drove home today in 3rd, the rpm was only maybe 200 rpms higher, than where it would normally slip in the 4th. But it did not slip 1 bit in third.

I also drove 2700 miles cross country in 3rd while towing and it was not all that bad.

I really think Im going to go with the 4.88s with 32s. The engine seems to be more happier there, no lug at all to accelerate