That’s a great little motor. But you can’t beet the cubic inches. Old 318’s should be a dime a dozen. A 60 over 318 makes 331 and with flat tops it would be a scremer. Or you could leave the 273 in. Just saying the money you spend will be the same. I had a beautiful 66 dart 273 hipo when I was 16 I put a 340 in it and never regretted it for one second. But that’s me.