This is in a 97 silverado k1500 with a 241c transfer case. I'm almost completely done with a 4l60e to 4l80e swap with a lq9 in front of it, using slider mounts i have adjusted the engine and transmission in place. I got a new rear drive shaft made and it fit within spec but now I need a new front driveshaft. I was thinking about ordering one i found online but I have a question about measuring. The advertisement states that it is 33.5 inches long (for a 97 k2500 with a 4l80e), which is almost exactly 2 inches longer than stock that came on my truck originally. When I go to measure from the front differential where the u joints go, and to the transfer case, does it have to be exactly 33.5 inches, or is it supposed to compress slightly while installed? Basically, if the driveshaft is 33.5 inches long from ujoint to ujoint, should i measure between the differential and transfer case around 33 inches or should it be exactly 33.5 inches? Seems like it should be or else it won't allow it to extend/compress properly when the front-end moves over bumps and whatnot, yeah? I know I should just have one built but I'm just wondering and if it'll work it might save me some time since the shop is a little far away from where I live and time is a little hard to come by these days for me after work and they're not open on Saturday.

 

The only real way to measure driveshaft is to measure u-joint center to u-joint center. I'm guessing you'll have to order a custom driveshaft because the C/K2500 8 lugs had the IFS 9.25" and you have the IFS 8.25". They are different geometry to the yoke.

I helped my brother swap a LQ4/4L80e into an 90 RCSB OBS, but a 2wd C1500. I think he slid the engine on mounts such that the factory driveshaft worked out okay.

 

The front diff does not move with your style of suspension.
The control arms and CV axles move. As long as the driveshaft can collapse slightly to fit between your yokes on the TC and diff, you're good to go.

 

I measured 35 inches between the front axle center and the transfer case center where the ujoint goes and found a driveshaft for my k1500 that would have come with a 4l80e, and it measures at 33.87 inches. I'm guessing it extends 2 inches like the stock one does. If so, that would leave me enough room, correct?

 

I measured 35 inches between the front axle center and the transfer case center where the ujoint goes and found a driveshaft for my k1500 that would have come with a 4l80e, and it measures at 33.87 inches. I'm guessing it extends 2 inches like the stock one does. If so, that would leave me enough room, correct?