Hi I know this info is probably out there already I looked couldent find it. Picked these up recently they are all 8jj 16r. I have disk break all around on a 1987 firebird fourmla. I was wondering what size I need on the front to not rub and have as much ground clearance. And in the rear I want a taller tire that’s a little meatier and is almost sticking out the wheel well.

 

245 is about the max of what is considered ideal for an 8" wide wheel. You can definitely go wider but I wouldn't go more than 255.

 

on the front or backs or both. And why wouldent you want to go wider, I don’t really understand fittment all too well.

 

If the tire is too wide, it causes the sidewall to balloon out. This will cause issues with stability and handling. Same with a tire that is too narrow for the wheel. There's a sweet spot for tire width in relation to wheel width. Just google recommended tire width for 8" wheel and you'll probably see a chart come up. If you're just wanting to move the wheel out a little farther toward the fenders and quarters, you can use wheel spacers. You might have to change the wheel studs though because the factory stud length will be too short for a large spacer.

Your safest bet is to go with the factory size of 245/50/16 for those wheels.

 

An 8-inch rim (the part of the WHEEL that the tire mounts on) is plenty wide for a 255mm tire width, however they "might" rub when making turns...

 

Nobody really gives a **** about the rim vs wheel debate. Thanks for taking the time to clarify though.

 

Well they should. Ignorance is nothing to be proud of...

 

What tires are on the wheels now? Do they rub anywhere? 245s shouldn't rub. 255s should be good also. But ride hight/alignment play a big roll. Also, the stops in the steering box have an effect.