Hey guys, what's the maximum wheel back-spacing I can use on the rear of my '74? It looks like there's a gob of room. I'd like to know before I mail order rims and have to send them back because they're wrong!
It lists several supposedly test-fit-proven combinations. As ElkyPete points out, wheels of similar dimensions by other manufacturers may or may not work as well (for example, backside profile may interfere with disc brake calipers - like older vs newer 14x7 factory steel wheels), but Weld claims these will fit. (a couple of their combinations don't make a lot of sense though, like the 4.625 backspace for 16x8 and 17x8 suddenly jumping to 5.500 backspace for 18x8, but that could reflect things like interior rim profile. Don't know.)
I don't know what the 'ET' column is. Weld customer service claimed it's the offset in mm, but I don't think I believe them because they show the same number in the 'ET' column for different backspacing at the same rim widths. Anyone who DOES know what it is, please let me/us know.
I'm actually thinking of using wheel vantiques 15 x 10 rally wheels. But that's if they can be had with the extra 2" on the backside of the rim, to give the wheel a stock appearance. That's my thought process anyways.
If you still have the factory drums in back, and are doing it only on the back, you MIGHT be able to make it work, although there is a good chance you will rub the tire on the inboard surface of the fenderwell. I'd try to simulate/measure a lot before ordering. Don't forget to put some weight in the back to compress the suspension when measuring, and allow for sidewall flex (which is worse with drag tires than street tires). Factory was 7", so if you keep the factory front bead position you are going a full 3" deeper into the body than stock. I'm just not sure there's that much room available in there.
At 15" diameter, I suspect if you go that deep into the car on the front you will have trouble with the tie rod ends when you turn. Maybe other things as well, but you'll probably hit the tie rod ends first. But it sounds like you are maybe thinking rear only (for improved launch).
Best of luck if you go for it. Let us know how it works out. You could always tub it, but it sounds like you are trying to keep the body stock.
Yeah, it'd be rears only. Mainly I want it for looks. There's nothing cooler than HUGE tires stuffed up under a stock rearend! The improved launch is also a good thing too. I've got a set of 15x8 vette wheels that I can use now, but even an inch more backspace would allow me to put a much wider tire on. I'm going for that pro-street look, without spending pro-street money!!!! :lol: