I had an 83 K10 sb & Iswapped out the 700r4 for a 4 spd out of an 86K10. The driveshaft length was the same on my truck.The output shaft on the 4spd is bigger than the auto,so I had to change the input shaft on my t-case.(NP208 case) I also used the "double hump" crossmember that fit the 4spd.I had to drill new holes in the frame for the c-member.I used the machanical linkage setup out of an 84 c10 pu.The hardest part of the swap was changing the pedal assy.from the auto to the manual.I used a torch & cut a small hole in the floor in the same location as the 84 for the rod to pass through,also cut the hole in the floorpan for the shifter to pass through.Also there are 2 holes in the frame for your clutch crosshaft to bolt to.On the 84 the crosshaft was riveted to the frame,so I torched the 2 rivets & bolted it in my 83.Whew! thats enough for now.