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Old 11-01-2016, 07:18 AM
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Default Back spacing
Can someone tell me the back spacing on the 15x8 snowflake rim....thanks

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Old 11-01-2016, 09:56 AM
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They are zero offset which equates to 4 1/2" backspace.

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Old 11-01-2016, 10:29 AM
oldsmobiledave oldsmobiledave is offline
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Default offset & Back spacing.
Quote:
Originally Posted by superdutybob View Post
They are zero offset which equates to 4 1/2" backspace.
I am confused. Isn't 0 offset on an 8" rim 4" of BS? Please explain.

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Own many Olds including
1972 442 W-30 (last 4 speed W-30 built);
1970 Cutlass W-31 #s match auto 3.91s;
1965 442 461 cid BBO & Richmond 5 speed;
1987 442 with 470 cid SBO 11.37 @ 119.4;
1972 442 524 cid BBO race car 10.89 @ 122.5;
1973 442 350 automatic black & white;
1980 GMC 468 cid BBO powered.

Past owner of an original paint 1973 Esprit.
Looking for the keeper 1970-1974 Pontiac F body.
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Old 11-01-2016, 11:16 AM
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An 8" rim measures 9" from lip to lip.

Backspacing is measured from the rear rim lip, hence the 4.5" backspace measurement.

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Old 11-01-2016, 11:38 AM
oldsmobiledave oldsmobiledave is offline
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Default offset
Quote:
Originally Posted by b-man View Post
An 8" rim measures 9" from lip to lip.

Backspacing is measured from the rear rim lip, hence the 4.5" backspace measurement.
Thanks. Silly me assumed that an 8" rim was 8" wide & 0 offset was half at 4".

__________________
Own many Olds including
1972 442 W-30 (last 4 speed W-30 built);
1970 Cutlass W-31 #s match auto 3.91s;
1965 442 461 cid BBO & Richmond 5 speed;
1987 442 with 470 cid SBO 11.37 @ 119.4;
1972 442 524 cid BBO race car 10.89 @ 122.5;
1973 442 350 automatic black & white;
1980 GMC 468 cid BBO powered.

Past owner of an original paint 1973 Esprit.
Looking for the keeper 1970-1974 Pontiac F body.
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Old 11-01-2016, 02:04 PM
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Quote:
Originally Posted by oldsmobiledave View Post
Thanks. Silly me assumed that an 8" rim was 8" wide & 0 offset was half at 4".
Honest mistake. The 8" measurement is taken where the tire meets the bead, not overall wheel width. I admit that it is confusing.

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Old 11-01-2016, 09:59 PM
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Ok thanks
I'm looking at a set of rims with 3 1/2 back space 15 x 8 rims
I want to mount some 275/60/15 drag radials to some rims but I don't think the 3 1/2 back space is gonna work any thoughts
I think the 3 1/2 will push the wheel to far out to the wheel lip...

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1973 Firebird Navajo Orange w/shaker,1973 400/461,1972 Intake SD CNC'd,1977 Q-Jet 800 CFM w/ Cliffs Kit,Tanks Inc PA4 255 Walbro intank pump ,-8an feed/return,RobbMc Regulator,RobbMc 40 micron filter,253 CFM 6x-8's w/H.S 1:5 Roller Rockers,SD Stump Puller H/R Cam 230/236 @.050 112 lobe separation 565/.570 lift,Crower Solid Rollers,28150 Hedman Headers,3" exhaust,full tailpipes,350 Turbo,9.5" 3200 Converter,3:42 gear,8.5 posi,C/E slide-alinks,Koni adj frt shocks,Best 12.18@110.55 Lookin for 11's
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Old 11-02-2016, 07:55 AM
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Question
Quote:
Originally Posted by cnc View Post
Ok thanks
I'm looking at a set of rims with 3 1/2 back space 15 x 8 rims
I want to mount some 275/60/15 drag radials to some rims but I don't think the 3 1/2 back space is gonna work any thoughts
I think the 3 1/2 will push the wheel to far out to the wheel lip...
I agree that it sounds risky. That's pushing the wheel outboard a full inch.

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2012 SRT8 Charger - 12.70 @ 111mph
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  #9  
Old 11-02-2016, 10:30 AM
oldsmobiledave oldsmobiledave is offline
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Default 255 60 15
If you don't already own the 275 60 15s the 255 60 15s work well & might leave you enough room to make that wheel back spacing work. I have 60' a best of 1.52 sec on a 255 60 15 drag radial on my G body with more power than you are making.

__________________
Own many Olds including
1972 442 W-30 (last 4 speed W-30 built);
1970 Cutlass W-31 #s match auto 3.91s;
1965 442 461 cid BBO & Richmond 5 speed;
1987 442 with 470 cid SBO 11.37 @ 119.4;
1972 442 524 cid BBO race car 10.89 @ 122.5;
1973 442 350 automatic black & white;
1980 GMC 468 cid BBO powered.

Past owner of an original paint 1973 Esprit.
Looking for the keeper 1970-1974 Pontiac F body.
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  #10  
Old 11-02-2016, 05:47 PM
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Hmmm that's some good info oldsmobiledave,...thanks Chris

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1973 Firebird Navajo Orange w/shaker,1973 400/461,1972 Intake SD CNC'd,1977 Q-Jet 800 CFM w/ Cliffs Kit,Tanks Inc PA4 255 Walbro intank pump ,-8an feed/return,RobbMc Regulator,RobbMc 40 micron filter,253 CFM 6x-8's w/H.S 1:5 Roller Rockers,SD Stump Puller H/R Cam 230/236 @.050 112 lobe separation 565/.570 lift,Crower Solid Rollers,28150 Hedman Headers,3" exhaust,full tailpipes,350 Turbo,9.5" 3200 Converter,3:42 gear,8.5 posi,C/E slide-alinks,Koni adj frt shocks,Best 12.18@110.55 Lookin for 11's
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