Need help with Wheel fitment

[D-n-Tyke]

I have been searching and reading for the last couple hours and am more confused then when I started. Hoping someone can help me with this. I am posting in the truck side as the traffic over here is much higher (and assume the suburban guys look over here just as much as the suburban side).

Found a set of Boss 338 for sale but am not positive they will fit on my Suburban. I know the only true way to answer this question is to measure my suburban but I am converting it and haven't installed all the suspension yet (still waiting on some parts).

Truck:
1969 C20 Suburban
Rear End = 1971 C10 5x5 lug pattern
Font End = Stock control Arms
CPP 2-1/2 Modular drop spindles
CPP 5x5 brake kit
Looking at going to a probably around a 3/5 static drop.

Wheels I am looking at:
Rears = 20x10 5.0 backspacing
Front = 18x8.0 4.0 backspacing

I am pretty confident the front will fit no problem it is the rears I am a little concerned with. I have read that people have run both 5.0" and 5.5" backspacing wheels on their trucks. Can someone help me out. I would like to try and go get these wheels today if they will fit but don't want to waste my time (2hr dirve) and money if they won't fit. Thanks for your help.

[lolife99]

If you have the wider 71-72 rear axle I would go with the 5.5” bs on a 10” wide wheel.

[D-n-Tyke]

Originally Posted by lolife99

If you have the wider 71-72 rear axle I would go with the 5.5” bs on a 10” wide wheel.

Thanks for the advice.
I agree if I was ordering them new I would order them with 5.5" bs ofcourse the ones I found are used and are 5.0" bs so am trying to figure out if I can run them or if they won't even fit. Again I understand they might not be as optimal as the 5.5" but running these used ones would definitely would be optimal to my budget build.

[geezer#99]

Do you trust that the seller knows how to measure backspace?
Did he provide pics?

Backspace isn’t the only consideration.
You need to measure your own which you wrote.
And you’re buying wheels way before you have everything installed.
Wheel/tire selection is usually the last thing you do.

[D-n-Tyke]

Originally Posted by geezer#99

Do you trust that the seller knows how to measure backspace?
Did he provide pics?

Backspace isn’t the only consideration.
You need to measure your own which you wrote.
And you’re buying wheels way before you have everything installed.
Wheel/tire selection is usually the last thing you do.

Yeah, pretty confident the guy knows how to measure the backspacing (although I would measure again when I could see them in person).

Agree, I am kind of putting the cart (wheels) infront of the house (suspension complete) but the deal on these wheels is about 1/4 of the cost to buy them new. Best I could do right now is measure with the stock '69 C20 rear end still in the truck.

[geezer#99]

If they’re cheap they’ll resell.
Can’t become a hoarder if you don’t start snapping stuff up.

[D-n-Tyke]

Originally Posted by geezer#99

Can’t become a hoarder if you don’t start snapping stuff up.

Hahaha. Very true. I don't know if my wife would love that outcome though.

[lolife99]

Do your rear axle swap.
Then any suspension work or drop.
Then measure for wheels.
Any other order of doing things is setting you up for failure.
Just my opinion.

[D-n-Tyke]

Welp learned my lesson on this one. Called the guy back up to arrange picking them up, and ofcourse while I was trying to conform if they would fit someone else already bought them. $1000 for full set of Boss 338 with rubber... should have gone and bought them and asked questions later. Dang it! Live and learn.

Thanks for all the replies.

[cab4word67]

I did that twice and then started to draw things out. I have a stepside 67 so I think I have less inside clearance. I ended up with 9x 20s w/4-3/4 BS and with a 1" spacer I and can run 275/40 20s