Ever heard of these?

[4trax]

A 5 blade billet aluminum impeller? are they pretty good? Cut to what ever size you need.

[YeLLowBoaT]

yeah I have... one of the tin boater can throw up a link. I know a few of them use them.

[SmokinLowriderSS]

I seem to recall one in a 130mph boat recently, was for sale in fact. Try e-bay. Was taking 1200+HP and surviving. :p

[centerhill condor]

yea, that ebay boat ran on liquid oxygen and jet "A"