Drive Shaft Install

[JR Dean]

Recently I installed a 350 SBC into my '63 GMC. When it was time to connect the driveshaft back up, there was not enough clearance to make the connection. I need about 1/16" more space. I remembered that when the engine mount stands were put in place that the mounting holes were lotted. It appears that if the 3 bolts holding each stand in place are loosened that the engine could be moved forward far enough to allow the drive shaft to be fastened in place. Am I on the right track?

[64fleetside]

Have you got the rear end off the ground? Sometimes that can help-easier than moving the engine.

[JR Dean]

The rear of the truck is raised with the rear tires in contact with the floor. Maybe the rear of the truck should be down to normal and the rear end assembly raised high enough to get the rear tires off the floor.

[JR Dean]

Thanks for the tip 64fleetide. That did the trick. There really should be another 1/4" gap at the transmission end to be safe

[luvbowties]

Originally Posted by JR Dean

Thanks for the tip 64fleetide. That did the trick. There really should be another 1/4" gap at the transmission end to be safe

JR, you are quite correct about needing more space at the tranny end--only you need more like an inch of slip-space. Else, the d-shaft is likely to hit & bust the tailshaft on the tranny. While driving, when the differential moves up and down it also moves closer to the tranny: the driveshaft needs play to move into and out of the tranny to avoid damage to tranny. You gotta have that play--either find one shorter enough to provide clearance or have yours shortened.

BTW and just for information: Shortening a shaft is much simpler than lengthening one. Find a buddy who has experience with them and it can be done without a lathe. Someone with experience can: scribe a straight line (to align joints back up; The u-joint flange assembly is made onto a tube several inches long and it fits inside shaft tubing snugly and 'perfectly'.); can carefully remove tubing of shaft welded onto flange; can clean up excess weld from flange's smaller diameter that snugly fits inside shaft tubing; can shorten shaft tube correct amount; then re-insert flange into shortened tubing and align scribed marks; and then re-weld flange to tubing. That u-joint's tube-diam. fits so snugly that even if driveshaft-tubing is not cut perfectly square, the u-joint tube will square itself to the larger tubing as it slides snugly into the tubing until it first 'hits'.
Don't try it by yourself as a 1st attempt--get knowledgeable help on your first couple of shortenings. I got help with my 1st 2, and have shortened several since then--never had a vibration either! But, I never twisted the engines 7500 RPM's, either!

[JR Dean]

Thanks luvbowties. That is valuable information. There is a machine shop just a few miles from where I live that does a lot drive shaft work and they do good work.