Performance questions

[docster]

I have a 2001 Yukon Denali. It has 120k on it. Drives good, all fresh fluids, no signs of anything wrong, yet. I will be towing a 6000lb travel trailer a few times a year. I have a few questions about upgrades.



It currently has CAI, and cat back, not sure of brands, and stock tune.



I plan on a tune for it

Maybe Cams (not sure if there are good ones that wont hurt towing).

Maybe long tubes

Used S/C kit if I can find one would be first choice.



At what point will trans need building? I come from Jeep world and my WJ with a 265hp 4.7 had same trans the 390HP Hemi have, so it was more than up to the task of heavy mods (which were few and far between). Not sure where these trans max out.



Ideally I would like a fairly reliable 380-400 chp and 400-450 ctq out of it. is this even possible?



Any info much appreciated.

I am looking for

 

[JennaBear]

Your desires are all reasonable, but your transmission will be the weakest link. No telling when it will go, could last a while, if you are conscious of the power you are putting to it.

LTs/cam/gears/blower would be a great start!

 

[destroyer1362]

My truck had about 105k when the tranny was rebuilt.. It was in need of a rebuild when I bought it at 102k though. At 104k I threw on some Dynatech SuperMaxx (catted) LT's, along with the Corsa Sport cat back. Really wakes it up. $2400 got me a stage 2.5 tranny (upgraded sprag, 5 disc clutch to a 7 disc, vett servo.. bunch of other stuff, I cant remember..) I tow a 6,000lb boat a decent amount, truck is at 126k and I dont really have any complaints.
The 4L65E thats in the denali is already pretty solid, I would say the LT's wouldn't hurt it.

Honestly my biggest concern is the transfer-case, I hear they are pricey to fix when they go..

 

[ccapehartusarmyINF.(ret)]

what kinda trailer ive been shopping for one?
Trans and gears especially when your towing kind of a heavy trailer
6000lbs is that dry weight? how does it handle it im lookin into about a 25 foot

 

[docster]

It's a 25ft airstream. It's 6000 loaded full. It's only about 4500 dry

 

[sbubbaklein]

might want to keep new trany in garage if your going to tow big loads. Then you can get best deal on trany price. It will be first to go

 

[docster]

Are you saying have a spare for the modded denali or for the stock denali? I was under the impression the 4L65E should be fine with the intake, exhaust, tune, and long tubes. Is that incorrect?


My plan for a blower and cams would be to have the trans built first. But those won't come until next year probably. Which is why I want to keep the trans as is if possible

 

[ccapehartusarmyINF.(ret)]

the 4l65E is more then enough if yer just doing intake exhaust and tune and long tubes
yer only talking 25 to 35 hp increase with those mods
i think the stock limits on a 4l65E is 400 ft lbs its a beefed up 4l60e to handle the 6.0

 

[Big Buttons]

Whatever you do you need to put a bigger tranny cooler on it. I have full bolt ons cam and stall on my 60e and it is still holding up. I drive like an ******* too (multiple launches a day)

I only have the tru cool 40K and a vette servo.

 

[ccapehartusarmyINF.(ret)]

yeah towing a 6000lb trailer you should already have that