On 73 - 87 full size chev trucks there is 22" of room between the outer frame rail and the inner part of the wheel well. So depending on fleetside or stepside and how low you want to go you can fit about a 20" wide wheel with out cutting the frame. You still have to deal with a narrowed rear end. As far as the suspension goes if you are to "pro street" or tub it, dump the leaf springs and go with a four link rear set up. Way more adjust ability and a heck of alot more traction. To see just how much clearance you have unbolt one of your beds inner wheel wells, knock it out and measure away. Good luck, James