Sizing up Bigger wheels

[yoshi]

How do I measure up for a set of wheels? I've got 15x7 modulars with 3 3/4" back space. I'm looking at some 18x8" ET +2mm & 18x9.5" ET -4mm but before I order I wanna measure up to see if they'll fit. I have a mustang2 front clip & narrowed ford 9" rear. Thanks

[geezer#99]

A tape measure and a few parts is all you need.
http://www.hotrod.com/how-to/wheels-...heels-fitment/

Or go high tech and buy a tool.
http://www.summitracing.com/int/part...1201/overview/

And I nice toy to see what looks good.
http://tbcwheels.ridestyler.com/?mode=webbot

[octanejunkie]

Need to know backspacing AND offset of new rims then the track width of the axles and body/frame distance from axle flanges.

[yoshi]

I've got the chance to borrow 20" & 18" wheels

[joedoh]

Originally Posted by octanejunkie

Need to know backspacing AND offset of new rims

did you maybe mean backspacing and WIDTH? because with backspacing and width I can derive offset, but with backspacing and offset you cant determine width... and knowing either backspacing or offset or even both without knowing width doesnt mean much. my money is you meant width haha.

and a simple way to know what fits is to use a plumb bob inside your fender (nut tied to a string) and measure from string to mounting surface. this is your max frontspacing. any wheel you find, take width +1 - backspace = wheel frontspace, and if that measurement is less than your max frontspace, you have a weiner, er, a winner.

you can possibly have a wheel that has so much backspace that it will hit the frame but chances are you would see how sucked in the wheel looked before you ever made that mistake.

[geezer#99]

Originally Posted by joedoh

did you maybe mean backspacing and WIDTH? because with backspacing and width I can derive offset, but with backspacing and offset you cant determine width... and knowing either backspacing or offset or even both without knowing width doesnt mean much. my money is you meant width haha.

and a simple way to know what fits is to use a plumb bob inside your fender (nut tied to a string) and measure from string to mounting surface. this is your max frontspacing. any wheel you find, take width +1 - backspace = wheel frontspace, and if that measurement is less than your max frontspace, you have a weiner, er, a winner.

you can possibly have a wheel that has so much backspace that it will hit the frame but chances are you would see how sucked in the wheel looked before you ever made that mistake.

That's a lot of voodoo mumbo jumbo!! Lol!!
What about cross section?