hello; first off if it has a two bbl carb it's a 360, all 390's from 67 up had four bbl carbs. they're right buy a rebuild book on FE's, read the hole book first, then decide what you want to do. it's best to bore the cylinders to straighten them up. if you only go to the next size you'll be able to rebuild it again if you ever need to. buy all your parts first so that the machine shop can bore and fit everything for you. turn the crank unless it's perfect and have everything balanced and cleaned good. good cast pistons and stock rods will be fine in a street motor. same with the stock cast crank. have someone with experiance do the heads, go a little bigger on the exhaust valves and open up the ports on the exhaust side only. use headers or free flowing exhaust manifolds and a GT 390 cam sence you'll probably be using an automatic. go with late model electronic ign and a good 650 or 700 cfm carb on a daul plane intake. you should be able to do this for about $1000 or less. good luck, wayne.