The suburban/blazer tank will be the easiest, I believe. Stick with 72 & earlier, there was a change with the 73 model. I bought a used tank, but it became a money pit. Didn't give much for the tank, but soon found that I would have to pay around $100 to have it boiled, and there is a big waiting list, only one shop in the area boils gas tanks now. Add to that a quart of tank sealer and sending unit, it soon became better to buy a new steel tank for $250 or so.
