You should get quite a bit better mileage than 9 mpg. My 64 292 with Carter 4 bbl gets 15 or so...not much different than what it got with the Monojet. It's got 4.10 gears in it and I don't run it consistently (if at all) over 65....usually cruise at 60.
I've driven "older" cars cross-country several times after buying them via the net. I've never had a serious problem. The worst one I had was losing a fan clutch in an 81 Monte Carlo. (I had bought it to tow a U-haul trailer with my son's stuff from North Carolina to Utah.) I had to change the clutch in the parking lot of a NAPA store. Took me 20 minutes. Oh...and I had to change a starter once in a parking lot. Dirty job, but not real difficult.
I've found these trips to be fun and a real adventure...like when I was a teenager and I'd start out on a "trip to nowhere" in a ratty old car and have to fix it with baling wire and waterpump pliers. Makes me wanna do another road trip.
I should add that I drove my 64 "Ugly Truck" on several road trips last year, including 2 trips to the Bonneville Salt Flats...once it was used as a prop in a movie. I had more trouble with my health than with the truck's.
