My first attempt at porting

[Goat Blower]

It's best to err a bit on the thick side for the exhaust housing since it gets very hot and is subject to cracking. It's more about having a smooth transition from the head to the exhaust manifold into the exhaust housing. Porting it out huge isn't necessarily a benefit. Porting out the exhaust manifold collector area and matching the exhaust housing is.

Looks good though.