6inch lift '72 long bed chevy k20 driveshaft?

[bignbad]

Ok i am getting told two different things about the rear drive shaft on a '72 chevy long bed k20 with a 6 inch lift some say i dont need to have it made longer and some do. So which is it? I know the front one will need to be longer then stock.And by the way its few local 4x4 shops telling me it along with other people. I am not getting a straight answer chime in please

[68panelman]

Any lift over 4" requires drive shaft lenghthing.

[72chevyk10]

Originally Posted by 68panelman

Any lift over 4" requires drive shaft lenghthing.

i agree

[special-K]

On the last '72 K/20 I put a 6" lift kit on I had to lengthen the rear driveshaft 2" and nothing on the front. Don't go by what anyone says. I have a 6" lift to put on my '72 K2500 (same thing,but GMC) and I'm not going by my own previous experience and making the rear drive shaft 2" longer in advance. I plan on doing the lift,then measure what I need on the drive shaft. I see no reason in the world this truck would be any different than the last,but I still would measure once I'm done. It will be right there looking me in my face telling me exactly what it needs...no ifs,ands,or buts.

[lukefalls]

Originally Posted by special-K

On the last '72 K/20 I put a 6" lift kit on I had to lengthen the rear driveshaft 2" and nothing on the front. Don't go by what anyone says. I have a 6" lift to put on my '72 K2500 (same thing,but GMC) and I'm not going by my own previous experience and making the rear drive shaft 2" longer in advance. I plan on doing the lift,then measure what I need on the drive shaft. I see no reason in the world this truck would be any different than the last,but I still would measure once I'm done. It will be right there looking me in my face telling me exactly what it needs...no ifs,ands,or buts.

x2. Outstanding advise!

[ryanroo]

i agree with special-k. install the lift and measure then build the driveling accordingly. it will not measure out that you can use the factory driveline even if you could physically bolt it in. it would be to short to work safely.

Special-k, if you made a driveline 2 inches longer for a chevy then it would not work for a GMC. the dana 60 and the HO52 are different enough that the driveline would not be the same. yet another reason your advice and plans are sound. (this is assuming you are working with stock trucks)

ryan

[special-K]

Ryan,that's a good point. I didn't mention I'm changing axles,too,and will be putting an HO52 in the rear and a Dana 60 in the front...with lower gears. I'm putting 12.50/37s on and the stock axles are 3.54. That said,I have a spare drive shaft here that is big and fat like these trucks have and it is 2" longer than what's in the GMC now. I'm assuming it's from a truck with an HO52?