Might consider putting some beefier springs in the front, perhaps a set for a Malibu station wagon. Out back, you'll want to put a stronger diff in. the S10 used the small 10 bolt, not really all that strong. Especially with a big block and larger tires. To keep it easy, try for a 10 bolt from a later ZR-2 truck. They use a narrowed full size 1/2 ton diff that's much stronger, plus the later ones have factory disk brakes.
For tire size, a 31x10.50 is about a big as you can go with the stock ride hight and fenders, anything bigger will rub. Being that it's already on an S truck chassis, probably would be around a 28" tire max diameter.
