[tmoble]

1. there can be. the early sub is rear steer and the box ends up sort of close to the firewall leading to sharp angles and multiple u-joints. I've seen several of these I wouldn't be comfortable driving.

2. I have a 70-81 sub under my 57 that's pretty low, I'm running 235/60r-15 on stock type 7" Ralley wheels. No issues with tire clearance, at least after I got rid of the poorly repaired caved in front fender. By pretty low I mean I have to work to get a floor jack under the crossmember. On this setup the steering shaft is an easy money deal. Mine has hardly any angle, one U-joint.

Be aware, the early Camaro front is similar to an early Chevelle as far as the basic geometry. The spindles are short and the upper arm mount is comparetively high, leading to a roll center that's well below ground level. This causes body roll, especially with the higher center of gravity of a truck body. This and the steering shaft deal are why I wouldn't choose the early Camaro sub-frame.

The 70-81 Camaro sub has tall spindles giving an above ground level roll center. The steering shaft is a no-brainer. You can use all stock GM parts for 12" brake setup, just need the spindles off a Caprice police car.

My truck has 70-81 sub with 1.25" stabilizer bar, 12:1 steering box and a 88 Vette rear axle assembly. It drives like a Camaro or Corvette.

All this, of course, is IMHO, YMMV, others have different opinions, etc, etc.