Ok here's my dilemma, I have a 91 RS with the grocery getter v6. I'm putting a carbed 350 down in it but I'm far from a trans expert. Not sure if the trans I have will hold up to a built 350. I do know I'm putting a 9'' rear under it and make g some serious suspension upgrades, just not sure about the trans. How do I find out if its a 700r or not?

 

You can check you RPO codes to help identify your trans, but you will not find good news. The 3.1l is a 60 degree V6, a different bell housing bolt pattern than that of a 350, or 90 degree bolt pattern. If the 350 is built just to stock standards, I doubt the trans could hold up for a drive to the mailbox and back, even if you could hack and weld one on.

 

OK, what trans would you recommend. A turbo 350 or a superglide. I can get either one fairly cheap. And would either one interfere with the new torque arm I plan to install?

 

700R. you can probably get a used one on this site. I have seen other members selling them all the time. That is was came in these cars so it should bolt in and work with the torque arm.

 

I am quoting this from another thread~ Use the search feature, there is a plethora of information on this site.


Originally Posted by bluegrassz

https://www.thirdgen.org/forums/tran...350-turbo.html

"Ok lets see if I can shed some light on this.

The 9" tail housing (long TH350) version is the same length as the 700r4. With the long version, stock driveshaft will work. Even my stock crossmember worked. I did have to buy a torque arm bracket , but thats cheap. You can get the Hurst or the B&M version.

I run 3.73 gears with a 26" tall Hoosier QTP tire. I could run 28" tires on the street and save the Hoosiers for the track. This would take some rpm out and be easier on the street. With the 26" tires, I crank about 3k at 60 mph.

The 700r4 does have a low first gear (maybe 3.06). But the gap between 1st and 2nd is wide. The TH350 1st to 2nd gap is closer together, so you dont have as much rpm drop if you drag racing.

Both trans can be built to hold quite a bit of power. The th350 will be cheaper to build comparied to the 700r4. Also the Th350 weighs less.

It all depends on how you plan on using your car. If its a DD then stay with the 700r4. If its just a hot street/strip and not worried about mpg, then the th350 is a great trans.

Oh yeah, if you do go with the th350, but a double o-ring dipstick like Lokar or a stock one with the boot type seal. Dont ask me how I know. lol "

 

I really do appreciate the advice. I can build a motor with my eyes closed. But as far as granny's go.....I'm a dumbass. Lol Never been brave enough to take one on. Thanks again.

 

Grab an f-body 700r4 core from the junk yard and dive in. Tons of videos on youtube, search the forums for how to rebuild and beef up~ You would be surprised and how easy it is, how few tools you need and what the results are.

 

https://www.thirdgen.org/forums/tran...ild-write.html

Here is my rebuild in progress thread

 

The gap, as you call it, is a non-issue, that's what the torque converter is for. For a TH350 to equal a 700R-4 with a 3.73:1 axle, the TH350 car would need a 4.56:1 axle for launching, and a 2.56:1 axle for cruising.
Once you try a 700R-4 that's working right and has a good torque converter, you'll never go back to a TH350 or TH400.

 

I absolutely agree with you~ I was just showing him what information is available if he uses the search tool.