Help with shock length!!

[LS-K]

I've got an '82 SWB K10. It's sitting on 33's with 15x10 wheels. So you get an good idea, I have no issues with tire rub anywhere in the tire wells. My tire to well gap is about a good 12".

The shlocks I'm replacing when extended measure 21" for the front and 27" in the rear. These two measurements seem a bit off, to me it sounds as if this truck had incorrect length shocks when I got it.

If anyone out there has a similar set up, can you please help me out with what length youre running in both front and rear? Or if anyone with a good knowledge on suspension height and shock length relation is out there please help.

I was never told this truck was lifted when I bought it, but in my best opinion, it looks to have a 4"-6" lift. I'll post pics of it tomorrow so everyone has a better idea.

Thanks for the help in advance.