budget 273 build

JJR said
The whole reason I bought the car was to get good at power shifting a 4 speed and because the car is slick looking. I have cut a couple good shifts, I am just not good enough at it to appreciate a higher horsepower engine. I believe the 4 barrel version in my GT had the high compression piston(10.5to1) and CP sells forged pistons to that spec for a 273. Cam lift for my GT stock is .425 inch lift and 248 degrees advertised duration for intake and exhaust. The only thing I plan on doing to the heads is gaskets matching and a three angle valve job while also retaining stock valve size. I realize shaving some metal off around the throat and bowl will definitely improve flow but I'm not going to get that crazy this go around. I also would like to put an aluminum single plane on it(edelbrock torker)for the weight loss and because it does not have the bends like the stock cast iron. I don't think the runner size is too big for this engine, it shouldn't hurt low end performance to bad. I was also definitely thinking about swapping the old AFB for a holley no bigger than 700 to 750cfm. I like the the idea of dougs headers with 1-5/8 inch primaries but for this build I think the tubes are a little big so I think I stick with the manifolds. Any ideas on what cam I should use for this combo. I don't know if a .500 plus lift cam would be worth it without massaging the ports. I don't mind a rough idle so a longer duration an tighter lobe separation wouldn't bother me especially if it pulls like a freight train on the upper rpms

I would not run a Torker intake. 318's and 273's have smaller intake ports than 340's and 360's. If you want a single plane, I'd go with a Holley Street Dominator or Offenhouser. But your best bet would probably be dual plane Performer, Mopar, or Weiand. A word of advise would be to keep your old AFB. After trying other carbs, you may find the old AFB works the best on the 273. Remember it is all about the combination. If running stock exhaust manifolds, I'd recommend a dual plane intake and a cam between 260 and 268 duration with springs to match along with a double roller timing chain. Get a good distributer with about 25 degrees of mechanical advance and set initial timing at 10 degrees BTDC. These mods would work with your 2 barrel pistons or 10.5 replacements. All things being equal, your 273 will rev higher than the numbers given by intake and cam manufacturers. If you are running higher than 5,000 RPM, and you should, I'd use a high pressure oil pump spring and a windage tray. Lower compression at full advance will run better than higher compression with retarded advance.