how can i tell if i have lowered spindles?

[lolife99]

I would stay 5x5.
Remember 5x4-3/4 is a car pattern.
Most of the wheels have a smaller center bore to match the car rotor.
There are actually alot of choices in the 5x5 pattern.

Another option would be to use an aftermarket 6-lug rotor.
They are a bolt-on rotor to what you have also.
That way you wouldn't have to do anything with the 6-lug rear axles.