Very nice. I had a lot of oldsmobiles over the years. Mine ranged from 68-71. The 330 is a good engine and with a well tuned carb you can expect 15mpg. Yes, same as your average large SUV today.
For wheels I suggest you get the Olds Superstock1 which is period and make correct. These are reproduced now for little money:
The later Superstock2 wheel is nice too and usually painted body color:
Keep us posted. You can PM me any time if you have Olds specific questions. I know everything about hot-rodding these, engine swaps, 3 or 4 speed auto conversions, etc. etc.
G