Engine builder questions

I ran a 273 with "72" 340 "J" heads. The 1.88's worked, but I centered the chambers over the bores with offset dowels and it took .040 to clean up the cylinders. I never notched the top of the cylinders. I'd mock everything up and check it real close to run 1.88's in a 273. I ran a stock 340 Cam. It pulled real strong.