The side tanks on some of the Chevy's got some real bad press a while back. they were mounted outboard of the frame and were subject to pucture during a side impact. I remember a hatchet job one of the TV shows did on Chevrolet about a fellow who was burned very badly in a crash.
We moved ours to get some more weight on the rear wheels. We are pushing over 500 HP on a stroked 350. Plus the idea of having all that fuel right against your back was a bit un-nerving.