how long will a 700R last behind a 350/350hp and possibly 75-100 shot for a car thats not driven daily. the trans works fine but is stock


87 bird
305
a few mods
700R4

 

Properly built, they will last a long time. My car has run 13.5's for about a year now on an almost stock 700R4 w/ 170,000 miles on it. I have been into TCI transmissions that took a poop w/ as little as 10K on the clock. 350/350 is really not a lot, so I'm sure a decently built 700 will last you a good while.

 

well, i had my 350 redone, edelbrock ported heads, ZZ9 cam with 1.6 rockers, siamesed runners, etc.. and my 700 only lasted about 4000 miles. It still works for normal driving, but when I get on it, sometimes it doesn't want to shift from first to second, and on those times when it does, it spends forever and a day between gears (2nd to 3rd shift takes forever as well). Plus, the trans used to shift really hard under all conditions, but is now soft and mushy.

Hope this helps

-Shaneo

 

Well my 700 has lasted for two summers behind my engine. Last summer it was totally stock aside from the 2500 stall and the giant cooler..... Late last year I put in a vette servo and a TV boost valve and it shifted a bit tighter. A few months ago I put in a Transgo Jr. kit and it really livened it up - shifted extremely tight for the 1-2 and 2-3. I did have some issues with the WOT 2-3 and WOT 3-4 shifts, but the trans really held up quite well. I recently spent a day on a road course though, and the trans hasn't seemed to shift quite right since... It hasn't completely blown up, but I don't know how much longer it will go. Keep in mind that I have no idea what kind of clutches are in it or how the clutches were setup.... It shifted fairly well from day one, but it really was your average 700 before I put some mods in it.

So the bottom line is that you can get a 700 to last without too much of a problem behind a motor like you are referring to. Getting the biggest cooler you can fit on the car is the most important thing you must do to have the trans live for any length of time. Frequent fluid changes also can mean the difference between life and death for a trans......

 

my buddy owns a tranny shop for 700 performance trannys he uses the transgo kit an xtra clutch pack your choice of auto or manual, billit servo, mech. diode new updated planiteries an billit 3rd gear slammer. he also puts the sun shell in crushed dry ice for 24 hours to make it stronger. a good cooler is also imp.we put one in a 85 , 375hp 350 with a 10 bolt 4-11 posi. the owner beat this car on a daily basis breaking a 10 bolt a year for 4 years before it broke. food for thought

 

Mine lasted 2 years to the day on my high 13 second car. I am doing it "right" this time