Driveshaft length

[71swb302]

I just got finished dropping in my 390/C6 combo into my 72 to find out my driveshaft is too long. Truck orginally looks like it had a manual in it based off the pictures of the crossmember I found on this site. The tranny in it now it a longtail C6, I got a rought measurement from the tip of output shaft to pinion yoke nut is about 55". My question is after searching this forum, some poeple were talking about using a later model ford aluminum driveshaft. Does anyone know what models/engine/bedsize of a later model truck I should be scouting for? Also how well do these shafts hold up to a 390's torque? Thanks

[Taylors69]

I would recommend finding a shop that rebuilds driveshafts and talk to them. We just completed an engine/tranny swap - took out a 3 speed manual and 240 and dropped in a 351 Windsor with an FMX - and we found a reputable shop locally that rebuilt our driveshaft to fit the new set-up. Make sure that you ask if the shop will spin balance your new driveshaft.

[michael69]

Put the yoke in the transmission push it all the way in then pull it out about an inch. Get someone to help measure and measure from the center of u joint cap hole on yoke to the center of the rearend u joint cup. That will give you the correct length drive shaft you need. Then go to bone yard and find the correct length shaft for about fifty bucks. The newer aluminum shafts will hold up just fine. That's what alot of drag racers use. Hope this helps.

[71swb302]

That helps a lot. I might just have mine redone. From talking to some local Scrapyards might be hard to find a good one that the forklift drivers haven't bent up.