Couple of thoughts: drive shower helps, but only if the pickups are below the cavitation plate. 1.32 was the alpha set for big block use, stronger essentially by ratio(teeth count), might want to consider a cryo process to improve gear life. Lastly, nose cone use is negligible at speeds under 80, which is why you can't find one for an alpha. I'm not against making a drive more hydrodynamic, but you really have to make it perfect or it will do more harm than good. Been some writing related to turbulence at water intakes. Decent water flow is important which has me wondering why someone would use the impellor only for the drive shower? I suspect a bravo seawater pump is used? Many bravo nose cones move the water pick up as well for higher X dims. Just my $0.02