I have a stock LQ4 and will be installing a Radix. I plan on going with something like the 3.0 pulley, and only other mods as of now are Supermaxx longtubes and high flow cats and catback exhaust. I'm torn on which way to go. I also think the TT3000 converter may be too much with the low end power of the blower and 2wd. I have traction issues without the blower! I figure both deals will cost about the same, so that's not an issue. I'm leaning toward the 4L80E (basically stock with servo's and shift kit), but I know it's not a direct bolt in. I'm also thinking the higher 1st gear ratio along with my measly 3.42 gears will be a benefit getting out of the hole with only 2wd. I need some opinions. I've searched a ton, and know it's been discussed, but I'm still posting this thread. Any input is appreciated. Thanks.

 

Those FLT transmissions are the real deal, personally I would go with the Level 5 FLT, but the 80 is not a bad option. I just think that the FLT 65 will hold up fine and perform a little better than the 80. Just my opinon though, but my cote is for the FLT.

 

I have an lq4 radix combo and the 80e is definately hurting my times. It a dogggg out of hole with 3.73's. It absolutely flies on the freeway and is a blast to drive after about 40mph, but it sucks out of the hole.

For the best times, put a solid built 4l65 in there.

 

If you can get by with a 65E then do it, talk to FLT to make sure he's confident he can build something to support those levels, I'm sure he will be able to. The 80E in strong and I don't worry about breaking mine anymore, but the gearing sucks from the hole as stated above. It might be better with the 2.75/1.75 gear set, I'll probably swap eventually.

 

how much would it cost to do a gear(1st gear) swap. I gotta tell, ya Tim, for what you want...a fast daily driver that is reliabe, it's hard to ignore the 80e. But everybody is right, I struggled to break into the 12's and it was due to weight and that trans. Everybod talks great **** about those flt-5's, but my theory is it isn't always HP that kills those 60e's, it's a combo of heat and weight w/HP-TQ(of course HP and TQ alone will kill the stockers). Keeping them cool is easy enough, but you can't trim your weight. You are 2wd, so that is a big plus on the weight factor. What is your weight? Being 2WD, I'd hate to be you on the decision process.Becuase everybody I know that has 65e's in their rides with blowers/turbos/n2o are F-ing flying. An SS with the same setup as me even gearing, except trans and wheels, runs 2 to 4 tenths faster than me. But, put me on the highway, not in 1st gear, ask Bryan how I run. She moves out.

 

I dont know why everyone needs a 4L80E? I properly built 4L60e can handle alot of abuse and expecially 500+ rwhp. Its who builds them and the stuff that they use that counts. I know a guy that has a 600rwhp Prochared ex cab that has of course a fully built 4L60E and drives the dog crap out of it and has not had a problem. The owner of the truck runs a shop and the same guy that built his transmission built some for his clients (F bodys that running forged motors and nitrous) They have had 1 break but the cars are 9 second street legal cars. Stick with the 4L60 they are stronger than you think.

 

I have a LQ4 Radix @ 7psi=450rwhp/tq. Vince/Chuck said the FLT 65E level 5 would serve me well as long as I didnt plan on putting slicks on my Tahoe and hitting the track often. I think the Tahoe weighs more than your truck so I think you would be safe with a 65E.

 

My truck is 4880 with me in it and the 20's. I figure on another 100lbs for the Radix, but the 17's are almost 100 lbs lighter, so I figure my weight will be about 4880 or real close. I haven't had any problems with my stock trans, but I'm not making any power either. It's everyone around here who has me paranoid as a **** about the damn thing! I emailed Vince from FLT a few weeks ago, and he said I would be o.k up to around 500 rwhp or so, but recommended the hardened shaft if I plan on putting slicks/sticky tires on it. I do plan on using some DR occasionally, but will mostly be on some kind of "daily" radial. I guess I'm thinking if I don't do the 80 swap it will always be on my mind. Do you Radix guys think the TT3000 will be too much for my 2wd and traction?

 

My Tahoe is 5800 with me in it.
I think the 3000 would be too much. First, traction is an issue for me and I have 24" rims and actually have some weight over the axel. I am running a 2600 TC. If I floor it from a stop it all A 3000 will however keep your rpm's up on the shifts. I guess its a trade off.
Second, the Radix is going to make a lot of power from Idle to 3000, you'd be skipping through a big part of that power band.