There are going to other deciding factors on how much it will slow you down. If there is a 15mph headwind your truck will be effected much more than mine. If you looking for the best ET don't put a lift on it. These trucks look absolutely mean with the front end dropped. Those things that happened to your truck are freak occurrences and chances are they would never happen again. With a 4" lift you probably going to with 35's? and they will be aggressive tread im sure that will kill your chances of running fast.
I know my 4" TC lift weighed 210 lbs and I took at least 100+ lbs off the truck that was removed to install the kit. I have every thing in a pile in the shop and have been meaning to weigh it but havent gotten to it yet.
I ran a best of 7.9 in the 1/8 at stock height and pyo's and 285 bfg's. With my 4" now and 305 bfgs and 16x10 wheels I still run a 7.9 so I dont think it will affect you that much except the 35's will be heavier.
Any regrets with the T.C. lift?
I also have a 4" Tuff Country lift. My axles are parallel to the ground all the time. If anything they are slightly up. I don't know if that's bad.
I didn't even pay attention to this until I went to race for the first time and there was hardly and adjustment left in the torsion bars (probaly 1/8" tops).
I race it just like it runs on the street and it launches straight.
Is it possible that the only difference in a 4" and 6" TC lift is the rear blocks?
FWIW I run 33" Mickey Thompson ATZ's with the lift and ran a best of 12.99 @ 101.49 on the stock turbo, full weight with a PPE tune.
i think once i have my trucks powertrain the way i want it to be i will start with lift and tires, seems everyone has good luck running the T.C. 4in when it comes to pulls.
I don't know about the TC 4" lift, but I know my Fabtech 6" won't allow me to mount a rim smaller than a 17" on my front end.
Just something to keep in mind.
If the kit retains the factory upper control arm, the 16" rim will hit it due to the change in geometry with the lift.
Only way I know is because my dealer had the lift done on my truck in a different city and they wanted my wheels so they could get it back. They said the stockers would not fit.
The TC 4" works great while racing. My CV's are a little negitive @ ride height, Wich is a good thing for both racing and pulling. You WILL be able to use your stock PYO's without any issues. I have my drag tires mounted to them. If your looking to get 35's in there it might not happen. I've got the stock BS on my 17x9 rims and they barely clear with 33x12.5's, with some triming in the front. But I do have the TB's dropped all the way down. My front is about one inch lower then the rear. The only issue I had, is a clunking sound while backing up. I tightened all lift bolts and found the sub frame loosened up. That was with about 1k mi. on the lift (Prob my fault), and has not had any issues in 20K mi.