driveshaft OK with swap from 8 1/4 to 8 3/4?

gstaples

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I'm swapping out the 318 spec 8 1/4 rear axle for a 8 3/4 unit I picked up a couple of years ago. I've read that the 8 1/4 axle centerline to yoke centerline is 11 7/8 and the 8 3/4 axle centerline to yoke/universal centerline is 12.35". It that enough difference to need a new driveshaft? I'm hoping this will be just a bolt-in and I can reuse the existing driveshaft. The spring perches and drum to drum measurements are correct for the 71 satellite/roadrunner. I'll probably upgrade to a 400/727 combo eventually and upgrade to a sturdier drivehaft at that time but was hoping to do the upgrades a piece at a time.
 

GTX JOHN

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I believe that it will be fine.
A 1/2 difference is not a lot and there
is usually plenty of spline engagement left
in the tail shaft.
On our race cars we used to run a AMC 904 yoke that is
a 1 or 1 1/2 shorter and it works fine even that much shorter and
less spline engagement and still sealed find.
We did it for weight reduction and NHRA never checked the part #s.
 
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