I have a 68 firebird with a 454 chevy with about 475 to 500 hp with 3.90 gear ratio and I have a turbo 400 but it needs to be rebuilt and I was wanting a 700r because of the over drive. I do alot of street racing and drag racing, but I always drive it on the street and I was wondering if the 700 would hold up to what im going to be doing. If any one has any ideas of witch one is better or knows where I can buy a strong 700 or 400 please let me know. thanks

Sorry i know this is in engine but I dont know how to move it to transmission?

Both trannys have their ups and downs. The 400 will be much cheaper to build, but it will use more hp (from what I have heard), and like you said, there is no overdrive. The 700R4 will cost considerably more if you want it to handle 500 hp, but it can easily be done. Other than the overdrive, one thing that may be good or bad about the 700R4 is the gear ratios and the gear spacing. The first gear in a 700R4 is 3.06 which is a lot lower than the 3.52 of the 400. This will give you way more torque off the line, which could allow you to not only have over drive, but also not have to run such a steep rear gear. The main thing bad about the 700R4 besides the price is larger spacing between gears, if you have a car with a short power band, you run the risk of bogging between gears. I think that with your motor having the torque that it does, you will not have that problem as bad as some cars. I had a 700R4 in a 72 nova with a 375HP 355. I loved it, and would pick it over a 350 or 400 any day in that applicaton. As long as I didnt shift before I was supposed to I never had any problem with bogging between gears. Here is a company that sells 700R4's that will handle up to 800 hp.

http://www.transmissioncenter.net/highperflist.htm

Good luck
Adam

There is only one person I can recommend to build a 700 that will not break hard parts or flair 2nd, Chris at CK Performance.

www.ckperformance.com

You will not be disapointed.

go to www.bowtieoverdrives.com They have all the info you'll need and then some. With a 700R4 you need to get a TV cable adapter and a lockup harness. I think you would be better off posting this on the tranny board. I've looked up the same thing and there are plenty of answers there. I just bought a 700R4 for my truck, it's going to be a little spendy getting it right. I need the TV cable, Lockup harness, possibly change the driveshaft length, and I may need a different crossmember. This is gonna add up quick.

Check out Yanks . You will not be disappointed with a 700R.

a 200-4R has a better 1-2 shift
Bowtie Overdrives will sell you one for $866-1284
http://www.bowtieoverdrives.com/cat...m.php?ITEMID=13