Looking for input on the 4.7 supercharger kits out there. I'm more of a turbo guy, but would like to see if anyone has run these and other than crappy mpg and some wear if this is a decent mod. The iron block for me is screaming to boost for some more hp and tq. Also has anyone took the leap into a standalone efi systems ( aem, motel, halters, etc)? Looks like it could remedy all th air injection/ emissions trouble this engine has.