What fits the best without doing wheelwell rolling? BONE stock body/suspension. I'd like to get the most rubber I can without scuffing the sidewalls. Thanks guys !

I have 17X8 with 5" backspacing on all four wheels.

I have 1" clearance between the wheel lip and 3/4" on the inside for the rear combination of 255/45R17 tires and wheels with a stock 64-67 10 bolt axle. I cut half a coil off of the back springs that lowered the rear
1/2". I also have not rolled the wheel lip.

The front tires are 235/45R17 and I have minor rubbing. It only rubs when the tire is at full turn lock and is pushed up into the wheelhouse. It rubs on the bottom of the wheelhouse, so no damage occurs. I would make one change on the front, I would use 17X7 wheels with 4-1/2" bs to cure this rubbing issue. This would move the tire in 1/2" and not affect the inside clearance. The front suspension has been lowered 1" with the Hotchkiss springs. I also have installed 72 Chevelle power disk brakes, which move the wheel outward about 1/4" due to the thickness of the rotor.

You may be able to use a bigger tire on the rear such as a 275mm width. This would be about 3/4" wider than I have on the El Camino and would still allow at least 5/8" on the outside and 3/8" on the inside. You can gain even more clearance by rolling the wheel lip. This is all based on a stock 64-67 rear axle, a later model 68 and up is 1-1/4" wider and changes all my measurements.

I believe that the El Camino and Chevelle rear wheelhouses are slightly different and that the Chevelle wheelhouse is smaller. It's best if you measure your rear wheelhouse and wheel mounting surface position on your car. It's easy to do, remove the rear wheels and then support the car under the axle tube so the axle is in the normal loaded position. Then use a straight piece of angle iron to lay against the wheel mounting surface of the brake drum. This should extend into the upper wheelhouse so you can measure the distance from the mounting surface edge to the inner sidewall and the wheel lip. Measure at the front, middle, and rear points of the wheel lip to find the smallest clearance available. Then put this data onto a piece of graph paper showing the relationship of the mounting surface to the wheelhouse sides. Next decide what width wheel you want to use and draw a box that is centered between the sidewalls. Then draw the centerline of the wheel. Now you can measure the distance from the mounting surface line to the wheel centerline and determine the backspacing required for your car.

Thanks Brian !