7 1/4 to 8 1/4 swap

-
depends on what tranny your using. ive heard that for a 727, its like 2 1/4" (DO NOT QUOTE ME!)

but yeah its dependant on ur tranny size
 
not shortening the trans end just the end that mates to the rear but its a 67 dart with a 904
 
73charger said:
ok..you still gotta let us know whay tranny you are using though
Click to expand...

If your not changing the tranny then it is is not relavent which tranny you have.

When I swapped the 7.25 to and 8.25 I had the drive shaft shortened 1.5". It's easy enough to check though. Put a piece of broom handle in the u-joint saddle on the 7.25 with it parralell to the axle tubes and measure from the center of the axle to the center of the broom handle, then do the same on the 8.25. Subtract the 7.25 from the 8.25 number and that is the amount you need to shorten it.
 
About 1" but if you just remove the amount from the drive shaft that represents the difference in the axle centerline to the u-jount centerline on the yoke then the play in the slip yoke will remain the same.
 
the reason I asked is it has about 1 1/2" play now and we are going to put some higher than stock springs in along with the rear swap which will increase the slip yoke play so I want to account for that when we take the measurements and I think 1 1/2" is the outside of acceptable range? am I correct in thinking 1" to 1 1/2" of free play?
 
Higher than stock springs will decrease the amount of slop at ride height assuming the distance from the locator pin on the spring to the front spring pivot is the same. The slop is at it's maximum at the stock ride height and will decrease as the suspension extends or compresses.

The radius of the arc that the axle travels in is much smaller than the radius of the arc the drive shaft follows. This makes the distance from the axle to the front u-joint less at the extremes of the travel and pushes the slip yoke into the tranny more at the extremes reducing the slop.
 
You must log in or register to reply here.
-

Back
Top