I've only got about 6 sets of the 20's and 19's - yes they are 50 for a 10". Stock fronts are 30 for the 9" wheels. The 'standard' rear wheel was a 9" with a 40 (I think).
The reproduction wheels are different offsets, and those might be 45's.
looking at the wheels while on the car with no tires i know that the rear will fit but i dont know about the front....im doing to upload pics, tell me what size tire i should go with on the front...there is very little room for sidewall bulge...