My new combo is reacking havoc on my drivetrain.
First the pinion in the 9 bolt.
Now I've lost 3rd and od in the 700R4.
I've seen some pretty stout packages out there ( Orr89rocZ and 1989GTATransAm to name a couple ) that are using these transmissions.
Who else uses them and at what power levels?
This trans was just a modified stocker with the ususal mods ( .5" boost valve, Corvette servo, shift kit etc ) with no band or clutch upgrades. I've got a ' built ' spare trans in the shop, however ....

 

Well, if you are beating yours up, I think I might be in for some surprises. I doubt I'll me making as much power as you, but the parts list is very similar for motor.
I opted for the beast shell, Kevlar band, as well as the Alto 3-4 clutches, and 13 vane pump after the TransGo shift kit. I went through the set of stock clutches learning what happens when the TV cable isn't set correctly on a WOT run.

I'd say, either wait until that one dies on you, or swap out for the built trans. Just so long as the current one isn't going to leave you stranded somewhere.

 

The problem is...they tell you they will hold 500 HP, they just don't tell you for how long.

The internals are quite small.

 

i have the top of the line 700 from bowtie overdrives with manual valvebody from trans-go, i dont remember the specifics for internals but.... ive got a hughes 3000 stall lockup converter, and a 370' gear. with close to 600 to the pavement, and no problems street drivin daily and run hard at the track nearly every weekend and still strong....

 

It looks as though the 3/4 clutch pack gave up. The trans has shown signs of slipping in OD, particularly when I'm trying to pass somebody.
My spare is ' supposed ' to have quality clutches and bands in it. I swapped it out when I was chasing a nasty driveline vibration and wanted to eliminate the trans as a possible source. ( no luck either )
I suspect my modest package may be producing 400 hp with similar torque.
I'm contemplating a TCI 700R4 replacement. I love the overdrive and like that I can run steeper gears out back and still get decent highway mileage.

My package is very similar to yours ( with less hp ).
Maybe a 700 is still a reliable choice.

 

Check the pinion angle. I had that problem when I did a rearend swap. Produced a horrible vibration after about 55mph. Also might want to try a different driveshaft just in case. I borrowed a friend's to rule that problem out.

 

i have 400+ at the wheels all motor and a 150 shot that hits right out of the hole. I have the kevlar band the upgraded servos (not the corvette got them from raptor trans) the 13 vein pump the good clutch pack, valve body etc all the goodies lasted me a summer and a half 10k miles.

fyi my kevlar band wore half way through the drum so that was replaced on the second rebuild
I had the full throttle 3rd gear shift issue and tried a shift kit on the next rebuild that only lasted about 5k miles other than the clutch packs going bad and the 3rd gear full throttle issue it was a pretty good tranny

now i'm in the middle of a t56 convert tired of rebuilding it

 

The 700r4 can be built to handle some serious power but its not as simple as some servos and and and a shift kits its making it all work together

 

care to elaborate on the combination that has kept your transmission from failing?

 

That's understood.
However, at what point is the 700 no longer a viable option?
Spending a couple of thousand dollars on a trans that'll break is the last thing I want to do.

 

I have been doing this for many years now, and making a 700R4 hold up and last is a easy thing to do. I have hundreds out there and others building there transmission themselves over the years holding up fine. Unless you have over 700FWHP and drive very aggressively, you should be fine with a built 700R4 and a good torque converter.

 

I've had other encouraging replies like yours. I'll be installing my
original 'spare'. It was rebuilt by a local fellow who insists that it will stand up to what I can dish out. This was after I returned the first rebuild to him when it stopped allowing engine braking in manual 1-2-3. As a value added service he upgraded the clutch packs to something a little more durable.
I have a TCI Street Fighter torque convertor that appears to be functioning well. If this trans grenades I'll have to drop the coin and get a professionally built unit.