Customs Torque converter help

I have a th400 with no torque converter but a buddy has a torque converter for a th350 . Will this work in my transmission?

 

A stock 400 is 13" and a stock TH350 is 12".
They are interchangeable, if you use the 13" converter in a TH350, be sure it clears the case.
If you are doing a TH400 deal, use the TH350 converter. Using a 12" in a 400 will give you a little higher stall speed. Your flexplate will need to match the converter.

 

They will interchange but a 350 converter has a smaller bolt pattern where it bolts to the flex plate. Most flex plates have a dual pattern so be sure to verify the bolt pattern.

 

Always heard when i was younger that it was a cheap way to get more stall speed.

 

If you could find a converter out of a TH350 equipped Vega, that was really the way to go. Until you toasted it, of course.

I run a modified 12" switch pitch converter from an ST300 2 speed automatic in my Th400. It's good for an occasional 9 second pass, when the weather is right.

 

Any suggestions for a converter like that?

 

You're probably better off talking to a torque converter company, and getting what they recommend for your vehicle.

If you want to learn about the switch pitch, I can help. It's a Turbo 400 thing, though.

 

I had a friend put together a TH400 for my 71 Nova he picked up a used Vega Torque Converter and it worked very well for my mild built 350 SBC engine. Of course this was back in the late 1970's when the Chevy Vega was still around in the Salvage Yard's and some people still driving them. I would think you would have a hard time finding one these days in most Salvage Yard's. So like Squirrel said get ahold of a Torque Converter Company and let them know what you have in the engine (Cam and so on) tranny type and gears and rear gear ratio tire size and what ever else they may ask you about and what type of driving you will be doing with your Vehicle.
Back in the day we had no problem finding good used part's in Salvage Yard's those days are long gone now my friend.

1Nimrod

 

Jim, any info would be appreciated.

 

If you have a Chevy TH400, with a case that's older than the late 1970s (they have the year on the tag riveted on the side of the case), you can install the switch pitch parts, and make it work. You need a pump assembly with the solenoid, input shaft, and torque converter from a 65-57 Buick, Cad, or Olds switch pitch transmission. You can use the smaller 12" converter from a 65-67 Buick or Olds ST300 transmission, instead of the 13" TH400 converter.

You also need a restrictor, which is a tiny cup plug with a .030" orifice, that fits into the hole in the case where the pump fits.



If the case is too new, it either won't have this hole drilled, or it won't have metal there at all.

Also, make sure there is a sealing ring on the new input shaft, it's very close to the drum.