As long as you have skinny/slippery rear tires that 7 1/4" will be fine, also don't go around doing massive peg-leg burnouts (wrecks the diff spider gears). Mine held up fine behind a built 360 Mag because I had 225/70-14 BFG Radial T/As on the back, then when I swapped in the B-body 8 3/4" I upgraded to 275/60-15 Firestone Indy 500s (discontinued now).
It may be a tad soggy off the line with the stock gearing and TC but it won't be terrible, it's not like you NEED to upgrade those before the car is driven or it'll blow up lol. Just be smart and take it easy.
Same with the carb, it might not be "ideal" but the only thing you'll notice is a bit less power on the top end compared to a 750 cfm or so. That can be upgraded later. I would definitely recommend a Performer RPM intake or similar though, factory iron 4-bbl intake is good but not great especially on something with a decent cam and compression.
