I have the chance to swap my 700r4 that is built to the moon for a built th400. Even with a very built 700r4 I am still worries about it. I am spraying with a 100 shot and want to go bigger but I am scared to do it with this trans. I dont drive the truck much so milage is not an issue. I dont know how it will affect my quarter mile time. If I do the swap I will go with a larger stall (3k most likely) but I am worries I may be maxing out my motor befor I get to the ned of the track. I am running 4:10 with a 28 inch tall tire currently. All I will have to do is buy a converter and have my drive shaft re lenghthened so I will be out about $550 or so. What would you guys do?

 

you wont have to worry about it, thats for sure. I think the 400 will rob you of some power, if you could get a 350 trans, you would be better off. IMHO

 

How high are you planning on spinning your engine? 4.10's, TH400, 28" tire in 3rd gear at 6500rpm puts you at 130mph or so. Where you'll feel the difference is in the first gear. 3.06 for the 700 and 2.48 for the 400. A good converter can make up for some of that, and the higher 1st gear might actually help you get out of the hole better. I would get one with a t-brake and let it rip.

 

If it's mostly for the track I would do the switch, you should pick up a bit of mph and a little better et due to better gear spread...just not as good of 60'. A built 350 should work nicely but a 400 would be bulletproof although soak up a few horses. Somewhere around 5800 thru the traps. The 700 will only go so long.

 

About 6200 is as High as I would spin this motor. If I do the swap I dont know If I will go as far as the transbrake but I will do a 2 step and a line lock off the same button. This truck is not track only but all I use it for is screwing around and maby pulling a small trailer every now and again. I currently have a TIGHT 2800 stall but I think I would go with a 3k ish stall.

I am shooting for 11's. I am currently at 12.47 with a 100 shot and I dont know if the 700 will take to the 150 very well.

 

I say get the TH400 and everything ready.... and just see what the ole 700R will hold... I dont pull the trailer for no reason..

Now why would you worry bout your RPMs?? 3rd gear is 1:1 in both Trans...


4L60E
First gear 3.06
Second gear 1.63
Third gear 1.00
Fourth gear 0.70

TH400
First gear 2.48
Second gear 1.48
Third gear 1.00

Only thing your changing is First and Second gear.....

 

I bet mine is built stronger........