318 carb questions

I would agree with the timing chain recommendation, see post #6. I'd always run a 4 barrel over a 2 barrel, even on a 273. If you don't get better power and even mpg you did something wrong. If stock, the 68 318 is the best 318 to start with, but not even close to advertised horsepower. Any stock 4 barrel intake will work as well as aftermarket. Look for a dual plane, 68-69 stock 340, Edelbrock Performer, or Weiand Stealth. A small single plane, Holley Street Dominator or stock 273 should also work well with your combination. As for a carb, you can use any 273 AFB or a 68 to 70 340 AVS. For a new carb, I'd skip the Holley and look for a Edelbrock AFB, AVS, or a Holley Street Demon (won't work with any of the stock intake manifolds). Assuming you have an automatic transmission, the transmission kickdown linkage is a must, see post #2. You will also need a new air cleaner to fit the 4 barrel opening and also fit under your hood.