He's right. It's a very common conversion. Don't be afraid to do it.
The only thing you really need to check is
oil pan clearance. Depending on the parts used, there can be a small interferance problem with the #8 rod and a Canton pan. It's not much, only about 1/8" or so.
After you get all the pistons installed, put the pan on without a gasket. Spin the crank a couple of times. If it hits, just make a small adjustment with a hammer.