Max front wheel size and offset for 69' Cuda w/ BB and chassis exit headers

My Car: 69' Barracuda Fastback with 440 and 1 3/4 Chassis exit TTI's

Hey y'all, I'm back again,
Just swapped out my fenderwells for chassis exit and got rid of the KH and went to the later Single piston calipers and 5 x 4 1/2 BP so I can finally get a bigger front tire on the car...Shopping now for some Steelies or Police wheels and wondering what the Max front wheel size is that I can use and what wheel offset is required.

I have no wheels here to mock it up so need to get it right when I order wheels, I'm thinking a 15 x 6 but see that they are available in many different offsets and don't know which is the correct one to use.

Any help on correct wheel offset or even pointing to a past thread on the subject would be immensely appreciated...Thx