Stock wheel well is only 12", So I guess yours in mini-tubed ?Are they stock type rims? How wide are you looking to go? My 68 is old school with 15x10 centerline rims N50-15 M/T's tires. I don't remember the offset of the rims but the fit under the car with stock rear 12 bolt.
Have you looked into a Detroit speed and engineering mini tub kit? They also sell a narrowed gas tank and you can get offset shackles to deal with the springs.Whiplash67
I have a 67 camaro with 572 bb 4 speed trans 12 bolt by mosor.
I need to narrow the rearend for wider tires, how wide should I go ?
How much do you narrow the housing, and can you still use the stock springs?