If you are considering 275/40, might as well go with a 315/35 in the rear. Same sidewall height but wider. You will need to roll the rear fender lip though with a 4/6.

 

275/45/20 on a 20x8.5 with a +30 offset. '07 Classic with a 4/6

 

That looks hot man!

Damn those are sweet! What year caddy are they?

Wow l love this truck, sits perfect and those NNBS 20's are perfect!

So you have a 4 / 6 ? or ??? Could you PM me your specs? I'd like to lower my truck a bit more and tuck 20's like that.

 

well i went and checked out the wheels and their not in very good shape, hence the price lol. but im trying to work another deal for a set of the 20'' gmc polished wheels. so will see how that works out...

im not lowered yet tim, but im planing to go with a djm drop kit. its lca's up front and a flip kit out back, drop shocks all around. and honestly im not sure on the wheels, ive never seen a pair like them before...

 

Guess I didn't read all the way through about the wheels the first time, but those aren't caddy wheels. They have the crest center cap, but are just gm accessory wheels