Front d-shaft only travels 3"???
 

I am wrapping up my alcan lift for my 85 and getting ready to have shafts made. My question is just about every thread ive read on front shafts says you need at least 6" of slip. I started measuring today and static I'm at 29.5". With the passenger side stuffed I get 28" with driverside stuffed I get 31". Im no driveshaft expert but isn't that only 3" of needed slip.

Go with what you have read or be ready to hear a loud clank at some point....

get it extended or it will come out

it is ALWAYS better to have it and not need it, than need it and not have it. Get the longer slip and you'll be set for when you lift it more :P More slip also gives it greater strength and less play in that joint.