First thing is to figure out what you have, casting numbers, how much is the block bored now and where will it clean up. What head castings do you have, find the numbers. What condition are the parts? Can you get just one piston? Before you spend any money, magneflux the heads you want to run and find what is the smallest bore that the block will clean up? Now lets get real. Run what you got. We are talking street car, young man, everyday driver, pump gas and decent mpg so he can afford to drive it. You basically want to build a 1972, 9 to high 8 to 1 compression ratio 340 with a 318 block. Forget horsepower. Get the pistons you first thought of if you need to bore the block. Use the 360 heads. Get a hydraulic cam and lifters somewhere in the .450 to .500 lift and 210 to 225 duration and a double roller timing chain. Find a used 340 intake, then go with a carb to fit the intake. Have the distributor recurved for high performance. Add a windage tray and high pressure oil pump relief spring. Balance the pistons, rods, and crank. 8 1/4 rear will be fine and the 3.21 gears are perfect. No need for low first gear trans, find a decent used 904 or 998 and get that car running and Enjoy.
