Gray Ghost

I am about to start getting parts for my daily driver's swap and I need help. My '70 Chevy 1/2 ton is not only my DD but a hauler as well. Being a deckbuilder, I carry anywhere from 500-1750 lbs quite regularly. Also I tow 2000-4500 once a week or so. My truck has been upgraded with 3/4 ton coils and one ton helpers so the weight is carried well, but I know this can put a strain on the tranny.

The motor will be a '99-'02 5.3 with a Z28 intake, injectors and fuel rails and a cam just past the regular RV grind [I want a little lumpy with my idle please ]. The target is 325 hp with factory Corvette exhaust manifolds and duals with 60 series Flows. I have a 3.08 one legger that I may upgrade to posi if the budget allows.

I thought the 4L60E would be ok, but I here tales of others saying go stronger, so tell me...should I be looking for a 4L80E instead?

chevellepowered

iTrader: (37)

6l80e is the best.. espeacilly with the low low first gear.. might be a lil exspensive,, but a 4l80 is a way better choice than the 4l60e, and ur towing,, i recomend the them i this order, 6l80e, 4l80e last 4l60e,, do some research on the 6l80e it will have u droowling over it..

Stu Cool

iTrader: (13)

If you go to any of the overdrive automatics you will want to drop your rear end ratio to the 3.73 range. That is where most of the tow package stock Chevys with 5.3 are. I have a 2001 Silverado with 5.3 and 4L60E and it tows 3-4000 lbs with no problem at all.

I agree that the 4L80E is a great choice if you will be towing a lot.

Pat

Gray Ghost

I'll more than likely do the gear swap at the same time...3.73's are nice. I checked into the 6L80's...man they are expensive! Got my mechanic checking into a source he has for a better price than $4500. Sure would like that tranny....betcha I'd get over 20mpg on the highway!

More than likely though it'll be a 4L80E.

rojs234

iTrader: (5)

That 20MPG highway shouldn't be much of a problem with any of the overdrive trannys. I have a 2004 GMC 4wheel drive with 5.3 and 3.73's.
With a camper shell and gear that I have to haul every day, it weighs right at 6000 LB, yet, it still manages 19MPG around home and 20-21MPG on the highway. It gets almost 14MPG pulling a 5000LB RV trailer on trips! Ron

chevellepowered

iTrader: (37)

i can get you one for $1500 if its still there, then u would need a controler.. i want it but i dont have the money!!.. and yea pretty much any overdrive tranny will help with gas.. the 6 speed will help u stay in your power more..

cam75w/ls1

iTrader: (2)

I'm a transmission builder and the 4L60e's are fine as long as you can cool it. The biggest enemy is heat and the most heat is generated while towing,torque converter unlocked. Once the torque converter locks in then it stops heating the fluid.

Gray Ghost

I wish I was ready but I am not...might be by late this summer or early fall.

I would love to get 20 mpg! I only get 10-11 highway right now.