How many using an A500 overdrive ?

mopowers said
From the research I've done, it seems the spline count is the same, but the spline angle is different between the 727 and 518, so to do the swap you'll need a 518 slip yoke. I've noticed some aftermarket yokes are advertised to work for 727 and 518, but I'd bet they just machine extra spline clearance to work with either. I'd be uncomfortable using one of those.

for what it's worth, when I put an A500 in my M body, I think I was able to reuse the slip yoke from the original 998 tranny..IIRC I just had the stock driveshaft shortened...or did I pick up a 7290 ujoint 727 driveshaft to have shortened?...that was 18 years ago and I'm getting old and forgetful