Opinions wanted: '75 Duster with 18" Boss 338 wheels 4.5"backspace

[340fourspeedDuster]

The car is a 340 four speed Duster with an A body 8 3/4 pushing 3.91 gears. Pump gas motor. Front and rear heavy bumpers have been replaced with fiberglass. Weld-in frame connectors.
All, looking to purchase 18" X 8" wide Boss 338 5 black spoke, chrome lip wheels (old school type) for the Duster. Rolled the rear fender lips in. Same size tire front and rear. Looking to go with maybe a 225 26" tall tire. Front end has 1.03" torsion bars, poly bushings, F & R. Anyone done this with this size wheel/tire combo? Any clearance issues?
Tire brand selections? This car will only be driven 2000 miles/year. Want sticky tires, not 60,000 mile ones. I want to purchase and install, with no worries about turning, rubbing etc.
Thank You in advance

 

[dukes69]

I have them on my 69 Cuda. Mine is lowered a little with firmfeel 1.12 torsion bars, poly bushings and tubular uppers.

 

[dukes69]

This is before the new front suspension parts

 

[72bluNblu]

What's the planned use for the car?

18x8 with only a 4.5" backspace is a terrible waste, that's my opinion anyway. With that backspace the widest you can go up front is a 225. It will fit fine out back, unless you figure that you'll have a giant cavern of a wheelhouse with a skinny little tire in it.

A duster with a rolled quarter lip will fit an 18x9 with a 275 out back with the proper backspacing, no problem. Same for the front. You don't even need rolled quarters or fenders for that. The problem is the backspacing needed isn't the same front and rear if you have an a-body 8 3/4 rear axle.

If you want to keep the backspacing the same, you could run an 18x8 with 5" to 5.25" of backspace. You might need a 5mm spacer in the back if you get to 5.25". That would let you run 245/40/18's all the way around. Wider than that and you need to stagger the backspacing front and rear. 255/40/18's are 26" tall and have a lot of great tire options, but you'd need an 18x9" and at least 5.75" of backspacing in the front, but still only 5" to 5.25" in the back to stay off the springs. Plenty of room to the outside in the back though.

But that's only if you want to run wider tires all the way around. I run 275's on the front of my Duster and 295's in the back, but I have a 1/2" spring offset in the back (and a b-body 8 3/4).

 

[340fourspeedDuster]

Plan for the car is a weekend driver that handles great. I have Hooker ceramic headers on the 340 so I cannot drop the car too much without worrying about headers colliding with speed bumps. The firmer torsion bars replacing the .875" factory worn out bars should help with suspension jounce.

 

[72bluNblu]

If that's the case, I would avoid the 18x8's with 4.5" of backspacing. You just aren't going to be able to run enough tire. I'm not saying you need to run 275's all the way around to handle well, you don't (although with a Duster you can!). But, if great handling is the end goal I would suggest at least going to 245's. That would still allow you run the same backspace front and rear, as well as being a popular size with a lot of good handling, softer compound tires. Ideally I think you'd still want 5.25" to 5.6" of backspace in the front and 4.75" to 5" in the back, but 5.25" all the way around would work with possibly a small spacer in the back.