Nice job so far... Good job matching up the transfers and the intake port to the manifold.
Looks like doing a reverse jug on that setup would be fairly easy if you got a way to weld aluminum... just build up on the areas that need to be covered and then match port everything, Could probably even build it up with that Alumaloy stuff if you can keep the metal clean and monitor the temperature.
I personally have no desire to reverse jug any of my engines, but it would be a great idea where frame clearance is an issue as well as making the exhaust system a breeze.
That 48 should make good power when you're done with it, maybe a little lower gearing and let her rev, but still possible to build a high torque engine this size too depending on which way you decide to go with it.