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**lolife99** · 07-28-2009, 07:57 AM

Well,... a 15x8 ralley has a 4" BS. So I would assume a 15x12 would require an 8" BS (to fit the same on the outside).
With that said. Here's a few other things to think about.
What rearend are you using? 67-70 style (6-lug) or 71-72 style (5-lug)that is 1.5" wider,... OR a 67-70 with conversion 5-lug axles?
Is it mini-tubbed? (Almost definitely required).

It''s actually better to use a rim that you have, (with no tire mounted on it),... and do the measuring yourself.
Just remember that a 12" rim will actually measure 13" outside to outside edge.

07-28-2009, 07:57 AM	#3
lolife99 67-72 parts collector,… Join Date: Nov 2002 Location: Mid-MO Posts: 22,685	Re: backspacing question Well,... a 15x8 ralley has a 4" BS. So I would assume a 15x12 would require an 8" BS (to fit the same on the outside). With that said. Here's a few other things to think about. What rearend are you using? 67-70 style (6-lug) or 71-72 style (5-lug)that is 1.5" wider,... OR a 67-70 with conversion 5-lug axles? Is it mini-tubbed? (Almost definitely required). It''s actually better to use a rim that you have, (with no tire mounted on it),... and do the measuring yourself. Just remember that a 12" rim will actually measure 13" outside to outside edge. __________________ Keith Convert to disc brakes. http://67-72chevytrucks.com/vboard/s...d.php?t=444823 Last edited by lolife99; 07-28-2009 at 08:01 AM.