jcob

Trying to decide on a transmission for my car. Either keep the 4l60 and rebuild it or go to a 4l80. Currently my 4l60 has a broken sprag but if I pull it out I plan on rebuilding it and upgrading it, bc its been a year and a half since I rebuilt it. I want a transmission that will hold up to 800hp. I have a 3400lb nitrous car. I like how it does with the 60 but I want something that isn't going to break. I'm looking around $800-$1000 more to upgrade to a 4l80 including the cross member, harness and drive shaft.

SCott5

iTrader: (40)

4L80. Stock rebuild kit with a good stall and it will easily do what your looking for

mikesimpalass

x2 on the 4l80e. I think at your power level, no matter how well they are built, a 4l60 is going to have a short life.
I don't make nearly the power you do, but I still went with a flt 4l80 in my car and I don't regret it. it is one tough transmission

Dark SS

iTrader: (6)

I don't think a stock 4L80 with a shift kit will take 800HP and nitrous for too long.

mikesimpalass

it doesn't take much for an 80e to hold a lot of power. if you get one rebuilt. have the trans builder dual feed the direct clutches, thats the week link on a stock 80e, once you do that, you will have one tough transmission. I don't know if it would hold 800hp at that point, but it's not far off. best thing to do is to talk to a competent trans builder such as roseller, jakes, flt, and they will be able to tell you exactly what needs done for your power level. in the end, a 4l80e that is built for 800 horsepower is going to have a much smaller parts upgrade list vs a 4l60 built for the same power.

jcob

Thanks for all the input, looks like Its going to be an 80. I am going to order jakes stage 2 rebuild kit with an had forward hub and a billet input shaft. I'm also thinking of ordering this shift kit http://m.summitracing.com/parts/trg-4l80e-hd2/media/images

GMCSIERRA5.3

with the jakes kit you dont need a shiftkit it will tell you how to do your own hydraulic mods

jcob

Ok thanks for that info. Saves a little more money

mrvedit

That is exactly what you need; IMHO the billet input shaft is a must.
As mentioned you don't need any other shift kit. Get everything from Jakes Performance.