New wheel backspacing
Greetings everybody. This is actually my official first post as I am a new member as of today. I've got a 69 camaro that I've fully restored over the last 8 years with a 526 hp/518 ft lbs torque 400 sbc. I'm about to get this baby on the road for my marriage as I just completed my second year tour to Iraq. Anyway, I just want to ensure I get the final touches correct to finish it out well. I understand how to measure backspacing on the wheel, though I'm not confident on how to measure bs for what is needed on a newly installed axle, WITHOUT the wheel. The camaro has disc brakes all around and am in need of some assistance of how to ensure the proper bs is ordered to whomever I purchase them from. In the front, I'm looking to run 17X7 wheels with 235/45/17 tires. In the rear I'm looking at a 17X8 wheel with 255/45/17 tires.
My questions are:
1. How do I properly gather the correct backspace to order that particular wheel? The axle is installed though vehicle is still on stands.
2. What is the power rating on a cast wheel, (american racing torq thrust II) as compared to a 2 piece alloy wheel?
I have a 2" front coil drop. I see others that have the drop, uses a lot of the 235's for the front. If there's any suggestions, warnings or additional info to research that is recommended, it would be really appreciated!