Funny you should ask this..
I just got a set of ones for 67/68... there is a TON more room for the tire to travel up.. Technically they arn't much wider, but the curve seems to offer more internal room.
I will post a side by side picture tomorrow that shows better.. on the set I have they weighed in at half the weight of reproduction inners. I was really happy with the fit and finish.
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"A ship in port is safe, but that's not what ships are built for."
See Bad Penny run the cones:
https://www.youtube.com/watch?v=8GUPPIX-92U
1971 Chevelle Wagon - Roadster Shop Chassis ProCharged Shafiroff LS and lots of yada yada
1968 Camaro - Project Track Rat - 440 RHS LS