From what i understand, the db2 and 4 share almost everything, including the housing, the DB4 is apparently just an updated model. Dont quote me on that, having a hard time finding consistant info.
My reading has told me that there has only been once or twice that someone has ran out of fuel using the moose pump. The application was decompressed and using 2 turbos, and had a knack for blowing head gaskets. The other not sure one specifics, but crapped the crank out the oil pan. So im wondering if the DB2 is really our limiting factor. I know the engine itself can sustain beyond anything im planning on making. Biggest thing im concerned with currently is dropping large amounts of money to not get where i want to be. aka moose pump /injectors and run out of fuel at 250hp. It would handy to find out, given bigger injector lines, just what can be had out of the DB2, and how big the injectors can be safely bored, and the longevity of them.