I've ran into a snag on my 4in lift install. my driveshafts are bout 2in short . anyone else run into this problem? 4in JFB superflex coils(bowlegged like crazy), no rad arm drop brackets, blocks in the rear. splines aren't showing but they're pretty much fully extended at rest. any suggestions? (yeah i know getem lengthend but that costs more cash than i've got now)

lengthening is really the only way you can go. If you can't afford it right now, just make sure you don't wheel or droop your axles. If I remember correctly the splines are about 4 inches long so you should be ok to drive around. I drove mine around with 1" of spline showing and did alright till I got the new driveshaft

Never heard of anyone having driveshaft problems with a 4" lift!!! :shrug :shrug

Some have had problems with the 6" but still alot haven't had them lengthened. Is your pinion rotated up to correct for the lift?

Pics would also help a little more too.

Never heard of anyone having driveshaft problems with a 4" lift!!! :shrug :shrug

Me neither, I've never heard of problems until people have gone up to like 8 inches..Need more info on you rig??

I agree, you shouldnt need to lengthen w/ a 4" lift. Did you keep the wedges on the perch when you did the lift, that will make a difference.

If the splines aren't showing you've got enough room for all the flex the rear will do in my experience. I wheeled mine like that and totally unloaded the rear, never had a problem of any kind. Well, nothing a D7 couldn't get me out of.
http://2bigbroncosnorthwest.superford.org/registry/vehicles/users/963/605/t_Jim_with_wheels_in_air.jpg

http://www.superford.org/registry/vehicles/users/651/399/Jim_with_wheels_in_air.jpg

well the splines aren't showing but it is at full extention. guess i'm just worried i'll blow em up in the middle of no-where

78/79's are different from 80+ The splines seem to be shorter

here they are
front
http://www.digitalpose.com/mbr/1/19853/p/312533_1120779046172061586_vl.jpg

rear
http://www.digitalpose.com/mbr/1/19853/p/312534_2571528918907923507_vl.jpg

completed the lift today. i adjusted the pinion angles and the splines aren't showing so i should be alright, right? :???:

you're fine. Best way to test is to jack up the back or front and let the fully droop.

you're fine. Best way to test is to jack up the back or front and let the fully droop.
i guess i take my lift at work for granted ;) i'm not worried about the splines poppin out as much as them just wearing and blowing up

keep the splines well greased and they should be fine. Do you have a hilift?

when the splines on mine wore out and caused a pretty bad vibration.

I have a 4" lift on my 79 F150 and have never had a problem. Forget about them and drive it!!!

i have a 79. i lifted it 4" and used the stock shaft. then i swapped a D60 rear in & kept the stock shaft then too. test the droop if possible. i still havent cycled my suspension to see how it flexes. AXE

I have about a 4" lift in the rear and I had about an inch of spline showing.

but that may be because I have an NP435.