The main downside of the 302 will be the fact it was a fairly limited production engine when it was new, and parts availability hasn't improved over the years. On the plus side, it's going to look more original, and it will be close to a bolt-in swap.
The 292 is rugged, recent-manufacture, and at least some parts will interchange with the smallblock V-8 line, making repair parts much more affordable. You'll have to do a lot more adapting to make it fit your chassis, however.
Jerry
