High HP guys running a TH400

[71Dragtruck]

As I've mentioned in a previous thread, I'm building a Reid case TH400 for a new motor build I'm doing, motor should be in that 1200hp plus up to 200 shot on a progressive controller (to be used for fun, unless it doesn't run 8's on motor LOL).

Truck should still be in the 3700# range plus driver when done, adding weight in places and losing in others, running a 32" tire that's more like 32.6" (next tire will likely be a 33" but same listed rollout as I have now) and went to a 4:57 rear gear. Motor should be shifting in that 7600-7800 range.


Anyway I'm going to put in a 2.10 first gear and have a couple choices, a good quality good for 1500hp helical set, or go all out with a straight cut set with billet reaction carrier. cost diff in Canadian $1575.

Is there really any need for the billet carrier option in my application, is it worth the extra $$$ with our dollar being crap right now? Should I do it to save the rotating weight, or not worth it?

Regan and Rick, you guys have a 1st gear swap, what are you two running for gears and reaction carrier?

[regan wilson]

I cant give you all the details off the top of my head but I can give a few. My transmission is mostly stock internals. I run a John Kilgore planetary (regeared stocker) 2.10 1.31. 4L80 E pressure plate with 4 discs and a wave plate (the wave plate helps take the shock out of the second gear change). Plus a drilled out center support bolt (moves more fluid). We cut the pistons down and run .080 koleen steels with 5 clutches in the drums. and a 20 year old Hipster Trans Brake. In all reality I am pushing the limits of this combo. Thats why I havent made any wide open runs in awhile. It stays healthy just running on the throttle stop. It doesnt take too long to start burning clutches or turning a 34 element sprag over backwards wide open. I've only killed one stock case in all these years. It finally knocked the lugs out of the case, but Im not scared to keep running a stock case. I have another case in the shop I want to start building with stronger and lighter internals.

I'm sure after I babbled all that you are still confused....lol

[71Dragtruck]

Yes and no lol, basically I have Hutch doing me up a trans main reason I’m going Reid case is so I don’t have to mess with shields, they are a pain it is a fair bit more, but something I wanted, trans will be overbuilt, truck is heavy and never know if I’ll add even more power some day, every time I set a limit to how fast I want to make it that limit goes out the door couple years later.

My trans will have mostly aftermarket parts, the reaction carrier upgrade is kinda the last decision I have to make, I had talked to him and we had decided to just go with the helical gears but for the extra cash I think I’ll just say screw it and go straight cut and billet carrier, my ratio I think will be 2.10, 1.40.

As you know always tough to tell where to draw the line at the cash to spend, I usually get quotes then plan on it being double these days lol.

[RICKSRAT]

I just had TransKing go through my 400 and went with some upgraded parts. Went with Coan 300M Main shaft, 300m Input shaft w/oem drum, Billet forward clutch hub and a 2.22/1.40 5 pinion W/straight cut gears. The cost difference to a 2.10 was not worth it to me. I will be changing rear gear out soon from a 4.30 so will get SLR closer when I change rear gear. I went from a 31x14 Goodyear to a 315/60/15 drag radial. So its going to get interesting. Trans has a JW bell and just had it recertified as well. Was told it was good for 1200hp with upgrades done.