My interest in the DB4 has very little to do with the increased potential for fuel delivery. As far as I can tell your Moose products do a fine job with that and still maintain good reliability. I guess its more like as per Stanadyne's website a DB4 can deliver higher injection pressures by far than a DB2. Say you combine that with a free flowing nozzle like your Moose Misters which can flow big fuel and bug pressure without wasting the spray pattern then what would you have? I'm thinking a lot better fuel ecoonomy, lower emissions, and still plenty of fuel. My understanding was a cou-le guys here had swapped DB4 internals into a DB2 skeleton so that the fitment would still work. These guys RKoch and Motrack seem never to post here anymore. The problem is I've never had a certified pump guy tell me he could or would make it happen. I'm pretty sure that mecahnical DB4 heads for V8's exist, Peninsular Diesel and a couple other sites that make hot 6.2/6.5 marine diesels claim a mechanical 4 roller pump, and it sounds like Towcat had seen some 8 cylinder applications in China. I don't know, many times I'm curious to try something as much for novelty and "can it be done" than I am for actually having a good reason for it.