[pritch]

Welcome from Utah!

Here's some answers:

1) Look at the side covers on the engine-if they are like 6" tall, 292 and 4" tall, most likely a 250. The 292 motor mounts will be off set from each other, too

2) You've found the best parts cat.

3) Good old 90 wt. gear oil

5) See number 2

Looks like a good project truck.