Yep. If you can kill a 4L80, even stock, I'll bet even GM would like to hear about it.... They can handle it.

 

When I do the trans swap, I was also going to do gears in the rearend as well.

With this transmission, what gear would you recommend I use in the rear-end?

I currently have a 3.73 in the rear with 4L60 and I want to keep near this setup. I really like mileage on the highway now, but don't want to lose at the strip either.

I hear the 4L80 has way different gearing than the 4L60.
In other words:
How can I compensate to make it back how I had it with the 4L60e?

 

you really can't get all of that if you do the swap. if you go steeper with your gears you will get the launch back but loose miliage up top, if you keep your stock gears you will looses some down low but keep your miliage. they do sell a diferent gear set that gets you closer to the gears on the 4l60 but i would just spend the money elsewhere and try and make a little more tq.

the delima with the 80 seems to be how much hp do you plan to make, if you are border line on needing one the tranny will most likely slow you down some, once it is in there you can easily make ALOT more hp without breaking it and go faster but untill you do it will be slower.

 

Parish,

Do I need an aftermarket converter?
What did you go with?

If you think its necessary, I was thinking the Tank TT 2600HD?
I didn't want one too drastic.

 

you dont need an after market converter but it will help ALOT, if your going from a 60 with no converter to an 80 with a converter you will probably be faster with the 80.

the 2600 is a very mild converter, you will be mising out on alot of ET reduction with that converter, need more specs on what exactly you want to do with the truck to coment any further on converters.

 

Let me give you more details....
-heavy extended cab 2wd
-it will be a 6.0
-comp cam (Dur @ .05 .212/218--Lift .558/.563) --maybe tad more aggressive if I get stall
-150 shot of nitrous (on occasion)
-eventually headers (within 6mo.)
Please remember that I drive this truck everyday in the city (mostly) and on the highway so I need it very reliable and streetable.
I plan on keeping the 3.73s in the rearend.

 

do you tow? if so how much weight, how often and how far?

 

Tow 2 Jet Skis nearly every weekend (about 3,000 lbs.)
usually only about 15 miles, but on occasion, we have towed them over 150 miles.

 

Hmmm, I was going with a Huges Performance 2600 stall....maybe I should reconsider. They are changing the gears for me though

 

Blownchevy are you going with the lowgear planetary with the 2.75 first gear.Those would work great with the 4.10s in your truck.Don't be chicken go with the 3000 stall.