About to replace the stock P-Zero tires of Front 245/45-20 to Nitto INVO 255/35-20 and Rear stock 275/40-20 to Nitto INVO 295/35-20 and place on the stock 20"rims. Does anyone foresee a problem? Thanks.

 

Why aren't you getting the stock size?

 

I only forsee one issue, which is with the rear tires. There's a lot of room under the Camaro fenders, we're running a 295/305 setup granted with very different wheels than stock, but still... there's room for wide tires. You can't get too wide in the front on stock rims before you worry about hitting the springs and/or spring perch, but only adding 5mm of rubber to the inside shouldn't be a huge issue.

I'm relatively sure you have the inner clearance with a 20" on the rear with stock offsets, you wouldn't with smaller diameter wheels. My concern with the rear would be you're mounting a tire designed for a 10.5" wheel on a 9" wheel, which is 1" outside of the approved rim width for a 295/35... everyone rolls there eyes at approved rim widths, but if you've ever seen a tire pull off a rim while cornering, it matters and can ruin your day... I'd just be aware of that.