67-72 101 lessons

[thatK30guy]

Ok, I want/need to "learn" about the 67-72 line of trucks. I have a buddy who bought a 3/4 ton C20 (or 30, can't remember) with a wrecker bed on it. He wants to make the truck a 4x4. He found a donor frame for his and will be looking to upgrade to DRW D60 and narrow 14FF for it.

Problem is, the donor K20 is not the usual rig with the married tranny/t-case. Its got a remote/divorce t-case and closed knuckle drum brake front. Big old Eaton rear, too. Tranny should be the SM420?

Ok, my lessons I want to learn about these years are:

What years ran the disc brake fronts?

What year began the married tranny/t-case?

What are the differences in leaf springs between all these years of 67-72?

What parts will interchange, swap, etc.?



I don't know what else to ask right off the bat, so as we go along and I read replies, I will ask more when I think of them. These questions above are the main ones I have no clue about these years. I grew up dismantling and studying the 73-87 years.

Any other tips and important info regarding these years of trucks that I should know about, post up your info.

 

[bp71k5]

The only one I'm pretty sure about is that disc brakes became standard in 71.

You can try here for more details.
http://www.vintagechevytrucks.com/index2.html

The other bit of info I've found when looking for parts is that there is that 67-68 interchange pretty well and so do 69-72, but the changes were more significant between 68 and 69.

 

[KansasTwister]

1970 was the oddball year because it had open knuckles and drum brakes, then 1971 had dsics and open knuckles, that is for half tons. Dont know about 2/4 and 1 tons though, but 71 was standard disc brake front.