If I can ask .... your wanting to run a low compression blown 454 then turn it into a carb'd (I assume) runner in the winter? Isn't that kind of trying to have your cake & eat it too?

Go blown & leave it.

As for using the '99 7.4 ... can be done but bottom end, compression, heads, springs, etc. are not really "blower material" engines without some added upgrades (IMO).

REGS