Looking to use a 275/60r15 Drag Radial with a 15x8 wheel. What backspace would one suggest? Looking to use either a Weld or Billet Specialties wheels. Anyone have a ny pics to share? Thanks

Hopefully someone else will respond with more information.

Before I had the frame notched I ran 26x8.5x15 slicks on the stock 7” wide rims. A buddy ran 28x9x15 ET Drags on a set of 8” wide convo pros but the spacing was off and even with spacers they rubbed.

I think what you’re looking at have a wider section width and are taller than the 28x9s he was running. So it’s good that you’re checking to get the right backspacing and feedback on fitment.

I would love to be able to this without a frame notch. Boy a 10" wheel would look awsome tho

I've run many different wheel/tire sizes in the back without a notch.
That 275/60x15 is a sizable tire. Depending on which brand of tire you buy in that size the section width is what needs to be paid attention to. The M/T drag radial in that size is a 11.1" section width and 28.19" tall. Nitto is 11" and 28".
Tire diameter of 28" is generally not the fitment problem, but larger diameters mean the tire is closer the frame at the back as the frame rails move outboard.

Also be aware that a wide rim on most drag racing tires is not the norm. Optimum wheel width is provided by the tire manufacturer in the specs for a particular size. It's all about the sidewall and footprint with the sticky tires. The M/T drag radial in a 275/60x15 recommended width is 8" with a range of 7.5" to 9.5". Just one thing you need to keep in mind when selecting wheels for a specific tire size and use.

#1 I've run a Hoosier 275/45x16 Hoosier A6 tire, it's 11.2" section width at 25.6" tall on a 16x8, zero offset wheel and a 10 mm hubcentric spacer to move it outboard. No touch.
#2 I've run a Hoosier 11.5 x 27 QTP bias slick, it's 11.3" section width at 27" tall on a 15x8 steel rally wheel with I believe was about 4 1/4" back spacing and the 10 mm hubcentric spacer. Tire very close at the rear of the frame rail and very very light touch when you would turn fast to the left. But would say rub not an issue when running a pure slick that doesn't see street driving, only straight ahead drags.
#3 I've run a BFG Comp Summer tire in a 255/50x16, it's about 10.4" at 26" tall on a 16x8 zero offset wheel and a 10 mm spacer. No touch.

#4 Currently run a Falket RT660 275/40x17, it's 11.1" width at 25.7" tall" on a 17x9 wheel with a 12 mm offset and run an 18mm hub centric spacer.

For me the name of the came is "no touch" when it comes to tire wheels fitting. Those first three tire/wheel combo were run without any concern for rub and fit. The super fat 11.5x27 Hooiser slicks at a 11.3" section width were the max i could squeeze into the wells in back without them looking out of place. And that tire never touched the quarter panel well lips. So never had to roll the lips to fit any tire, lips are bone stock.

Those Falken 275/40x17 are very close in width to the 275/60x15 you are interested in running, just not as tall. I would not tell, say, exactly what backspacing/offset you could need with your combo. A lot of minor factors add up to moving the wheel inboard or outboard to achieve a good fit of a fat tire in a Monte.
Rear brakes whether stock cast drums, alum drums, an aftermarket disc setup,, swapping the rear for something other than stock, or something as simple as the rear being a little offset left or right of center. All these effect tire fit.
A note here about my fitments, my 8 1/2" rear has drum brakes with alum drums, they adds 2.5mm each side (about .100") to the width of the 8 1/2' rear. As mentioned silly thing can effect the final fit.

So I would first decide what exact tire you want to install, pull the specs, and then look for a wheel that is available in the width for the tire and then what available back spacings are available. Error on backspacing that moves the wheel inboard. A hubcentric wheel space can then be used to move the wheel/tire outboard to adjust the fit in the wheel well. That was my method to use a 11.1" section width tire on a 12mm offset wheel (only offset available in my wheel choice). An 18mm spacer was made to center the tire in the well. But be aware that smaller than a 10mm spacer may not be available.

Those Falkens are a 200 wear autox tire, I was stuck with using that tire in a 17" size. Hindsight says i could have choose an 19mm (.0394" more) and maybe not take the paint off the frame in a very very small area when I lean the car over hard. One milometer can make or brake a good fit.

Here's who I had make spacers for my car. Would never do anything but a hub centric spacer. They are pricey and if money allows get them black anodized.
I run the old 10mm set up front and the new 18mm on the back. Also longer ARP wheel studs to make me feel safer.
If the car is a serious drag race car be aware that wheel studs are a safety inspection item, NHRA has a say in the length.
https://www.uswheeladapters.com/shop/chevy-5x4-75-12-1-5-hcso/

Hope i didn't confuse you and you get a little opinion from this.
Bob

Thanks for the information. I want to run the MT ET Street SS 275/60r15 on a 15x8 wheel. These spacers seem like a good choice if needed. I currently have the 11" drum brake setup on a Strange housing. I know of someone that used this combination on a Grand National with a Weld Aluma Star and a 4.0 backspace. He had to use a spacer on one side of the car.

I would assume the need for that much tire means this isn't being done for looks or the cool factor. Don't laugh, see it at the car shows all the time.

Couple questions. That 28.2" height can mean a couple things. In a drag car used in the 1/4 mile the final gear ratio going though the traps is determined by a few things, trap mph, tire diameter and chosen trap rpm.
Running 1/8 mile same process, but just all different number to optimize mph.
Here's good calculator to arrive at the trap numbers, the reason tire diameter is important.
http://www.wallaceracing.com/calc-gear-tire-rpm-mph.php

I ran a BFG Comp II street tire at 26.1" as my every day tire. First drag tire tried was a set of M/T 255/50x16 ET Drag Radial on the recommended 8" wheel. Nice tire at 26.1", a 10.3" section width, 9.4" tread width. You could drive them to the track, and even out for ice cream, but stay off the wet stuff. Maybe 4 times out, 16 runs, and never got a good 60' with my stick shift launches. I gave them to a friend with a 67 Camaro, stout 350, 200r with 2900 stall on a 12 bolt, 4.11. Those tires worked well on his 3200 lb car with an auto trans. They are installed full time on his car.

Talking with others about hooking a stick car there are lots of thing to look at and some things to try. A local bracket racer of national acclaim was heading out to the West for Nats and bought new tires for his Malibu. Right place, right time, a good used set of Hoosier 11.50x27x15 QTP were in my van for 60 bucks. All i need is 10 or 20 passes out of them, they still had that left in them.
First couple passes 1.7s, last couple passes 1.7ish. As suggested by some the bias ply QTP liked my 700lb clutch launches better then the M/T drag radials. I know 1.7s are not good 60s but was happy with the ease of the launch. More passes on the car would have netted a little lower 60s Those taller, 27" QTP dropped trap rpm 10%, installing 4.11 was done for a trap rpm at 5800, it's a truck engine. .

Those QTP tires were on a 15x7" rally wheel, I think I said 15x8 previously, an 8" rally was an uncommon size. Found my note on that tire wheel combo and it said 4" backspacing, also not the 4 1/4" i said. So a 15x7" wheel at zero offset would be very close to what i ran and used the 10 mm to space it out.

I can't tell you exactly what wheel backspacing you may need. Just know that those fat 11.50x27x15 on an old Camaro rally with a 10 mm hubcentric spacer and thicker alum drums squeezed into the wheels with a light tight that was not an issues.

Those Camaro rally wheels came with my friends 67 Camaro roller purchased in like 05. They were the back wheels with an OLD, odd, M55x15 tire on it. We had all them F, G, L series fatter tires back in the 70s. Those super fat section width and lots to tread width I put on my car and tried to burn them off. I knew the rubber was way to old and just wanted to see if that really fat tire,11.3" fit the car without rub. They did after the 10mm space went on. I actually made several passes at Cecil County with video just trying to smoke up to l launch and test for tire rub. I'm not a tire smoking guy but it was fun using up the rubber on those junk tires.

Like others here I've run a few different tires on my old car. But in the past year have reduced the wheel and tire collection a lot. Previously had 18 tires on hand for the car, 14 wheels. Only the current four tires on the car, the Falken RT660 275/40x17 are around. The 15x7 steel rally are gone, gave them to a 69 Camaro friend.
Have 8 black, zero offset, 16x8 GTA wheels. Two very nice, near cherry sets to package and sell, a hard sell today.

I've got a few pics and video of the fat tires on the car. PM me if you want any.
Bob