[Yukon Jack]

I agree that a 4" lift is a great lift size. Modifications are kept to a minimum generally. BUT, your talking 1967 and that is different from the more simple to lift 69-72 years. There are a number of threads that address issues specific to the 1967 within about the last 4 months. If you can't find them, let me know and I will try to locate them for you. They will be a source of very good info for you.

Put a set of 33"s on your truck and you will have a nice appearance, but your tire won't be as heavy as a 35" so your mileage won't be as affected, and a little less wear on parts. These are bricks on wheels of course so realize a lift will affect your mileage if that is a concern.