M/T and ProComp wheel backspace question

[CaneyCat]

I'm looking at getting some new wheels for my 89 Blazer, I want some 16x8 procomp 7069's but the only ones they have are 4 inch backspace and the stock wheels are a 3-9/16ths. Will they work on my truck or is 4'' too much? I looked at the M/T Classic III's (I'd like to get the procomps as they are a good bit cheaper and look the same imo) but the only one with 3-5/8's backspace has a -22mm offset and all the other wheels I look at are around a -12mm offset and i'm not really sure what they mean by that. Any help is appreciated, would like to get it right the first time. Also sorry if this gets asked a lot, I did a search but didn't find anything.

 

[CaneyCat]

I've narrowed it down too two M/T classic III's. Both with 3-5/8 backspace, but one is a 16x8 with -22mm offset and the other in a 16x7 with -8mm. Can anyone tell me what I need?

 

[K85 Octane]

4" is fine
Mine are either 4.25 or 4.5", can't remember. But my rim is 11", so the tire and all stick out some.

The MM offset, I don't know either.

 

[CaneyCat]

Thanks, if 4"will work than I can get the procomps and save some money (with that saved money I'll get a CK5 membership )