Modified a 75 c 10 frame for my 1956 gmc . Ending up using a shortened 2wd . Which is shorter then my longbed but 3ish inches longer then a shortbed. But I always thought the 56 shortbed was stubby looking! So I made a medium bed! Did all the shortening in the bed box. And steps! Took stake pocket cover off .ran a tape line 3/4 in to keep factory bolt holes in place. Took 3 1/2 out . Welded up. Put pocket covers back on! Looks awesome! Having a lowered looking truck! I took out a wedge off top of frame,where cab mounts. Took each side and moved to opposite side,welding on bottom. Boxed most of it. So it looks lowered with stock front suspension. 4 linked and panhard barred the back with 3800 lb coil overs! In process of wrapping it up! Sbc,5spd. Medium bed! Also I used 16x6 and 16x8 so the tires spacing looks good. Perfect fit! Wanted to keep stock rear end and front end as much as possible! So I could get over the counter parts ,as much as possibly! Daily driver,will pass to my grandson if he grows up to respect it and keep it in the family! Learned not all do! When son sold a 52 Pontiac hardtop I gave him! He sold it for 1500 . What a punch in the jewels! Anyway ,will be watching your progress,can’t wait to see what you come up with!
K signifies the 4wd and the C signifies 2wd….. look up c10, c20, c30 vs k10, k20, or k30. The blazers are all k5. Gmc uses 15, 25, and 35 as a designation for the weight rating but still uses C and K
The C is 2wd and a K is 4wd. I have 1 of each chassis since I’m doing two of these swaps. The 10 just means half ton Chevy truck. 15 would be the gmc half ton.