Dixon ZTR replacement engine

[tractorface]

The 28M707 Briggs and Stratton engine on my 4421 ZTR is leaking badly. I had it apart earlier this year to replace the crankcase seal and the engine was damaged (by a previous owner. I have it back together but with JB weld mending a broken bolt hole. This means I probably can not replace the now pourus oil sump. I can try and patch the sump or buy a replacement engine. It is a 13HP verticl shaft engine that turns 3300Rpm. I am thinking of using a Honda GVX390 as a replacement because I like how quiet they are. Thought I'd run it up the flag pole here and see if anyone had any suggestions.

Thanks