Front Driveline Lengths

I have an 85 chevy silvarado k10 (short,wide), and have a 6 inch standard lift kit (skyjacker). Obviously the front driveline shouldn't be extended all the way out.  What length would give me the proper suspension travel? I have also installed a transfercase lowering kit but the driveline is still extended too far.  

I think you will just want to order a custom shaft from a place like Reel Driveshafts or something. I don't think you can have one that has too much travel. I have seen a homemade shaft made out of two lengths of square tubing, one with a slightly smaller I.D. than the other. this allowed almost unlimited driveshaft travel. If you want an exact measurement of the maximum distance, measure from the diff pinion to the Tcase when the axle is at the lowest point as compared to the frame as expected during operation. You will probably have to disconnect the factory shaft to get this measurement. Once you got the full extension measurement, measure the for the compressed position of the driveshaft. Now that you've got numbers, start shopping.  

No, you do not need to order a expensive custom drive shaft (many seem to think you do though) You can take current drive shaft to a good drive shaft shop and they can cut ends off and weld them to a new and longer tube and balance it too for far less than a new drive shaft. Add a few inches to current length but, you need to EXTEND your bump stops that limits upward/compression travel of front axle because with a longer drive shaft if you bottom it out and stock stop with a longer driveshaft you could jam/bind drive shaft between axle and Tcase and break something. (likely Tcase)  

Yeah that would be a cheaper route to go. I went with custom because I got mine for free.  

The most expensive part of a drive shaft by far is the hardware on the ends of it. This is what make retubing then very cost effective.