Posi rear differential factory option?

[Mike C]

Originally Posted by special-K

What I am saying is that is incorrect or incomplete. My actual life experience says different. Sorry to disappoint you. A manual truck did not come standard with 3.08s in these years. I showed you two trucks I actually owned. I never read your book. I can show you more trucks, though.

Tim, My ‘72 Jimmy is a factory 4 speed 350 and came with 3.07 gears. Or am I just not understanding this? The 350 V8 came with 3.07 regardless of transmission choice standard with options of 3.73 and maybe 4.10 in the half ton.

OP, I haven’t seen anybody else say it, but if you change the rear gear ratio in a K truck (4x4) you have to change the front to match. Several people have mentioned the 3.40/3.42 gear, but I don’t think you can get that ratio in a Dana 44 gear set for the front.

Unless someone has removed it, the Dana 44 in the front should have a ratio tag specifying what gear is in it. And if it is anything other than what that engine combo came with stock, it will be an option on the SPID.