Hi Racer, if the 5.0 engine you are talking about has the 3" stroke, and the 4" bore, it might be a little small for the application. Compared to the chevy 302, I believe the parameters are very similar. While there are plenty of after market parts, most of the horse power comes in the higher RPMs of the smaller cubic inch engines. I have heard of the small blocks turning 10500 RPM thru the lights during drag racing, but longevity is usually nonexistant. You could probably build a 5.0 using later heads, rods etc., but you will still be limited by the cubic inches.
As for the PSRU, look up geared drives, and call Bud. He is a wealth of information, and could have what you need. Don
Are we talking here about water-cooling of the engine? Real heavy weight burden. Being new, I ask lots of questions, but intuitively realize weight is of the essence in flying, is it not? That said, how in the world did B-29s receive adequate air for cooling purposes at 30,000 feet? Just wonderin'! jack
Water cooled can have a weight penalty, it's true. It should be noted though that a couple of the lightest in class engines on the market today are water cooled, namely the rotax 912 series and the D motor. Being in the 100 hp class that's saying something, too, as it's easier to get a good power to weight with larger engines. Just sayin'.