Driveshaft Math, Someone Double Check Me?

[toofun]

I have a tko 600. According to classic chevy 5 speed the tip of the rubber boot is 3/8's past the start of the tail shaft spline. My current driveshaft yoke sits about 1 1/4 inches TO THE RUBBER BOOT. Which if my math is correct would put it at 1 5/8's from the tail shaft (1 1/4+ 3/8's= 1 5/8's) I would like to end up with 3/4 of an inch from the yoke to the beginning of the tail shaft.

My measurement of my current driveshaft from center line to center line is 47 inches. So if I am looking to get a FINAL clearance of 3/4 of an inch would that mean that I would need to LENGTHEN the driveshaft to 47 7/8's FROM CENTER LINE TO CENTER LINE??

I am pretty sure I did the math right but if someone can double check it for me I would appreciate it!!

Thanks
Mark
TOOFUN

[toofun]

I am venturing to say that MATH is not anyones strong suit on this site? No matter... I went with it and it worked out great

[OHCbird]

Sounds good- the addition of 7/8" should put you where you want to be. Does this give you enough spline contact on the output shaft, and does it give you enough hanging out so the yoke doesn't bind (say under acceleration, where the pinioin climbs & pushes the dshaft forward)?

oops- didn't see your 2nd post...