C4 swap, can't get a drive shaft to work

[blue83ranger]

The mustang driveshaft i measured (3 inch) bolted on the transfercase (backwards of course) and it bolted to the rear end too. If i get another mustang shaft, would it even work if the only slip joint shaft i can find is the 2 3/4 or should i just find another 2 3/4? and will 2 3/4 be big enough to make 67 and 5/16 long?

 

[bottledgt]

i dont really think 2 3/4 is big enough,. call spicer, they have a chart that will tell you the length cut offs for your max rpm and shaft size. the problem is, with a slip yoke, it cuts down the max length drastically. if it were a solid shaft it would be different

 

[Mutant Pony]

Many driveshafts that long are bigger in the middle. You will need to get a slip yoke that bolts in and then measure the length of tube you need.
I had a '69 Gmc years ago, reg cab long box, with a saginaw 4sp. The drive shaft was 70 something inches and was 2 3/4. It went over 100 mph many times and did donuts on dry pavement many times. The drive shaft never had a problem.(other things did!).

 

[blue83ranger]

I got really lucky and found a shaft that'll work. I just need to put flanges on both ends and have it shortened. I'm pretty sure it's out of a '79 f150 4x4 reg. cab long bed, it measures roughly 71 inches long. the tube size is 3 1/2 and i measured the u joints and the mustang flanges will fit. when i get it in i'll let you know how it turns out. and one more question for ya, Do i just take out the cross memeber and go or should i move it somewhere else. (does it help keep the frame sturdy or is it ONLY there for the 2 peice drive shaft.) thanks again for all the help.

 

[Mutant Pony]

A lot of guys here have just removed them and not had a problem, It is in the tech somewhere I'm sure. Your case was a little different because of the tranny but, the crossmember issue is the same.
I'm glad this is working out for you, I'm getting a little noise from my carrier I'll be getting rid of it soon.

 

[blue83ranger]

I got my drive shaft back from being shortened and balanced a few days ago. Even got a free paint job out of it. It looks really good (couldn't even tell which end was cut) but i haven't test drove it yet at 55. I'm sure it'll be perfect, the place we took it seems pretty popular and people send them stuff from California so they would almost have to be good.