after market wheels on 67 gto, would you stay with 15" rims and big tires or up to 17" rims (both 8" wide) i've beefed up the motor, but still have 3.55 in rear, all thoughts are appreciated

i'd stay with the 15's personally.

i'm not a big fan of the rubber band look and i perfer a tire with some sidewall for a couple reasons. they ride better and they'll give a bit of warning before breaking loose when pushing the car thru a corner.

mike

I went for the compromise on my 64. I put 16x8 all around, then went with bigs and littles for tire sizes. My gears are also 3.55's so i went with 16 to get the same diameter as stock (27) and handling ability. the rear tires are 235-60x16. The fronts are 215-55x16.
I've also replaced bushings with poly-graphite, and the front springs with Hotchkiss lowered. The car handles like a much newer car, yet retains the old school flavor.