295/40/18 & 18x10’s (A Body)?

[sn75]

Anybody running this size tire on the rear of their A Body? Any pics?

I’m considering 18x10’s with this size tire (Forgeline’s or the like). The height/width of this size would be ideal. 295/45/18 and 305/45/18 are too large/tall. 285/40/18 “might” be an option in a drag radial only (drag radials aren’t offered in the 295/40 unfortunately, but I can live with that). The 27” to 27.5” tall, but under 12” width range is what I’m shooting for.

As for backspacing, I have a 1” shorter 12 bolt (.5” each side) and was thinking 5.65” b.s. to keep the wheel centered but not get too close to the outside inner fender? Thoughts?

[csouth]

10" is a common width for 68-72 A bodies with 5.75" bs. I shortened mine .5" each side with 5.75" bs and there is no rub. Reducing your backspacing would be fine.

[sn75]

10" is a common width for 68-72 A bodies with 5.75" bs. I shortened mine .5" each side with 5.75" bs and there is no rub. Reducing your back would be fine.

Ok. Some have told me to go with 5.5” b.s. or it will not be centered and will rub on the inside/inner fender. Honestly, I don’t see that happening if I go with 5.75” or even 5.65”. Sounds like you’re in agreement with me?

[csouth]

Ok. Some have told me to go with 5.5” b.s. or it will not be centered and will rub on the inside/inner fender. Honestly, I don’t see that happening if I go with 5.75” or even 5.65”. Sounds like you’re in agreement with me?

You'll be fine... Like I said (and this is without knowing your year), 5.75" is the most common backspace used for GM A body on a 10" wide wheel. I'm running 19x10 with 295/35/19

I just ran to the garage and took a pic for you.

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[sn75]

Thanks for the pics. Mine is a ‘72. Looking to ditch the rollers I’ve been using during my build/engine swap (heavy/played out Coys 18x8/18x9.5). Suppose I could go 19x10 w/ 275/40 or 285/40 tires. 285’s would be around 28”, but narrower than 295/40/18’s. Decisions, decisions.......

[csouth]

Thanks for the pics. Mine is a ‘72. Looking to ditch the rollers I’ve been using during my build/engine swap (heavy/played out Coys 18x8/18x9.5). Suppose I could go 19x10 w/ 275/40 or 285/40 tires. 285’s would be around 28”, but narrower than 295/40/18’s. Decisions, decisions.......

I would have gone with 5.75" backspacing on 18's in the rear if I did them. If you are nervous, you could rent the wheel fit tool that is posted in the parts section.

[cdrod]

I'm running 285|40|18s on the rear of my '72 442 Convertible with a stock-width rear and 9" wide rims with 5.25" bs. I'm happy with the look of extra wide rubber in the rear don't have any clearance issues or rubbing. My car isn't lowered much so that may play into my easy fitment. The earlier year A-bodies have less room for wide rubber than the later years.

[Typhoon1015]

I would spend the money/time to buy or borrow a mock-up tire and a tire fitment tool to verify clearances. If your spending good money on rims, you do not want to guess based on other users experiences. You would want to use that as a guide only to get close. Measure twice to be sure.

[andrewb70]

I used to run the Flaken 295/40-18s on my 70 GTO. I have 18x10.5" wheels with 6.25" of backspacing. Fits like a glove and never rubbed. My outer wheel well lip is slightly rolled (maybe 1/2" extra clearance than stock). YMMV...

Andrew

[sn75]

Yah, I measured based on what I currently have on my car and accounting for extra tire width and 5.75” will be perfect (and plenty safe without looking sucked too far into the wheel well). Would be pushing it with any decently wide tire running 5.5” b.s. (not gonna risk it).

[USAZR1]

If you decide to run an 18x10 w/5.75" backspace, with that narrowed rear, those 295's will be sucked in much closer to the inner frame rails and inner wheel tubs. You will have more room from the outer edge of the tire's sidewall to the outer fender lip.