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View Full Version : 1970 firebird.. 18x9 backspacing?

70Firbird
08-20-2008, 10:56 AM
Can anyone help me out w/ the backspacing for the front for an 18x9 wheel.

thx
redfire69
08-20-2008, 01:16 PM
5.25 with stock suspension.
70Firbird
08-20-2008, 02:04 PM
will it rub anywhere? I dont mind dramatically rolling my fenders outwards to avoid any rub by using a smaller backspacing....
brownz
08-20-2008, 06:59 PM
will it rub anywhere? I dont mind dramatically rolling my fenders outwards to avoid any rub by using a smaller backspacing....

that should be fine with just the fender lips rolled and you may not haft to do that with the bird quarters. i have a 79 Z28 witha 18*9.5 rear with 5.5b/s fits great
redfire69
08-21-2008, 02:48 AM
will it rub anywhere? I dont mind dramatically rolling my fenders outwards to avoid any rub by using a smaller backspacing....

it shoudn't rub at stock height. If you're lowering or have weak springs you may get some contact with the front outer WW. I've heard guys running smaller BS like 4.5 (front only) and are still OK, but a little more gives you the option of lowering 1-2 inches. There is a lot of talk about BS w/18X9s over at the YO bandit forum:
http://www.yearone.com/yodnn/bandit/BanditForum/tabid/104/forumid/2/scope/threads/Default.aspx
OLDFLM
08-21-2008, 05:56 AM
SW's red TA was running (CL205s & TTIIs) 18x8f w/4.5"bs and 18x10r w/5.5bs with 255/40/18f and 295/35/18r just for a reference. I'm running a little more (.25") bs front and rear with 255/45/18f and 295/40/18 rear. I'd HIGHLY recommend you call Jon @ DriverzInc with your backspacing questions. He'll help you nail it the first time!!
V/R,
Ty
markss28
08-21-2008, 08:06 AM
18*9 in the front is a little big especialy if you have stock control arms. I think 18*8.5 would be enough and clear everything at a 4.5 BS. Just my opinion.
brownz
08-21-2008, 06:24 PM
that should be fine with just the fender lips rolled and you may not haft to do that with the bird quarters. i have a 79 Z28 witha 18*9.5 rear with 5.5b/s fits great

sorry thought this was for the rear LOL:lol:
72OBSESSED
08-24-2008, 06:10 PM
make sure that you take your brake set-up in to consideration. i have a 72 camaro with an 18x8 w/5.25bs with a 245/40/18 and wilwood 12" dynalites and i could have gone with probably another half inch more