max spacer size

[tandk22]

I know there has been talk on spacers, but is it bad to run 1" spacers on the rear and 1/4" spacers on the front if I replace the studs, since I want to buy these used wheels. I have a 69 camaro stock suspension front/ rear with a 9" rear end. Rear wheel is 18 x9.5 but the back space to outside of the wheel is 6" and I only have 6" of clearance from the mounting surface to the inside well. Front the back space is 5 1/4" to the outside of the wheel and I have been told 4 7/8" or 5" is optimal???? Sorry I seached for answers and could not come a conclusion about max spacers safe to run. My camaro will not be a race car but driven hard. thanks Todd