18's don't fit looking into 20's need HELP

[cutlass11]

Yes you read right! I have a 72 cutlass supreme with an ls engine 6 speed t56 full UMI suspension set up for protouring. I have raced the car a hand full of times now at willow spring raceway and its AWSOME!!!! I had issues in the beginning of course. Power steering pump, suspension set up, rear sway bar. But I was able to really dial the car in and had a great time. She's not a show car by any means (plenty of dents and rust with all red primer) but I still get complements at the track.


Ok so to the point, the car seems plenty fast with about 470hp to the wheels but the brakes need to be upgraded. Mind you I have 2002 Camaro calipers front and rear with drilled and slotted rotors. I came up on a set of CTS V brakes 6 piston calipers and 4 piston rears. So I made it work with my set up. Had to open up the center bore of the rotors to slip over the hub. An had to drill out the mounting hole for the calipers to 9/16. Front calipers and rotors now fit. So to my problem. My current wheel is the Ridler 650 18x9.5 0 offset which should be 5.25 backpacking. I was under the impression they would work.😣😣😣😣 but the wheel contacts the caliper. Just barely! But I dont want to grind down the caliper to make it work. Plus I would have maybe a 1/8 of clearance. I dont like that idea.




So bigger wheels it is! I would like a 19in wheel but who even makes one???? I see alot of 20in wheels, was planning on just going to the same Ridler 650 in a 20x10 and I would like the same wheel on all four corners for front grip and ease of tire rotation.


Any other track guys or gals running large wheels??? What size and backspacing? Again I currently have a 18x9.5 with 275/40-18 square. I'm thinking 20x10 with 275/35-20 or a 295/35-20 if I wanted to go wider. I'm asking for anyone's help or input. Thanks in advance, oh and I am literally waiting on responses before I make a purchase for new wheels and tires but no rush.