dfire25

Hi guys,
I am changing from a th400 to a 200-4R in my 71 442. Unfortunately the yoke from the th400 doesn't fit the 200-4R. So what size yoke do I need?

Thanks,
Dave

olds 307 and 403

One from a TH350 is also the same. So a drive shaft froma TH350 should be a direct swap, same length as a 2004R.

dfire25

Thanks olds.

Does anyone know the length of the drive shaft for a TH350? Maybe I can just get a new yoke and use the old driveshaft.

oldcutlass

The drive shaft will need to be about 1 inch longer I believe.

svnt442

You can't use the TH400 shaft with either a TH350 or the 200-4R because it will be too short.
I believe though that the 200-4R uses the TH400 mounting location so that will allow you to keep your existing parking brake cables and hardware (if they're not rusted to hell.....I grew up in the Chicago area so I know how that goes).

kitfoxdave

The TH350 driveshaft on my 72 cutlass fit just right with the 200-4R. about 3/4" of exposed shaft on the fwd end going into the seal of the transmission. The crossmember fit perfect at the aft location for the TH400. you might want to do a slight bit of trim of the lower flange where the crossmember hides one of the transmission pan bolts. It will make it easier to drop the pan, but you can get along without doing that as well... Best of luck with your install.

dfire25

Thanks for the help guys.

I would still like to know what the length is for a TH350 drive shaft though.

It's complicated so I'll try to explain.

When I purchased my car it had a 350 installed in it and it came with a 455 that needed to be rebuilt, in fact it was in pieces. My intensions were to rebuild the 455 and drive the car till the 350 blew up. Well the 350 blew up a lot faster then I expected So I pulled the motor and trans to get ready for the 455. That's when I discovered that I had a long shaft TH400 installed not the normal short shaft . What the idiot did was install the motor and trans so it fit in the car and he welded the frame mounts to the car at the location where they fit . Yeah I know, they were even upside down. They weren't even welded that good, I got them off with a screw driver and my bare hands .

So needless to say I have now idea where my driveshaft came from. That's why I would like to know the length to see if I can salvage my old one.

Thanks again,
Dave

joe_padavano

The easy answer is to put your engine and trans in place where they belong. Insert the yoke into the trans and bottom it out. Pull it back out one inch. Now measure the u-joint center-to-center distance. This is the driveshaft length.

By the way, the yoke for pretty much any GM RWD trans EXCEPT the TH400 (and some Muncies) fits a 200-4R.

dfire25

That figures that my yoke is from a TH400.

I'm trying to line up a driveshaft while I'm still waiting on the motor to be completed. Then when I install the motor I'll be ready to go. So I still need to know what a TH350 driveshaft length is.