SB 318 Wanting to build for a 67 Dart GT

Yeah, I think you're misreading the casting number....probably the last digit is a 6 or 8. The first thing to do is to make sure the block will clean with just a hone. Unless you have a real thick walled block, you're at the stock limit when it comes to boring. The 302 casting heads will work fine. Double check to see that you have a 727 as the stock transmission that year was a 904. If it turns out that it's the original 904, you'll need to get a reducing bushing for the end of the crankshaft to center the small snout on the stock converter. If you plan to do anything but putt around, I would consider going through the transmission and make upgrades, depending on the horsepower you end up with. If you plan to use regular pump gas, keep the 9:1 pistons.