Ebay twin turbo setup Checklist...Turbo a SBM for under $1000? :)

The math:

So a mid 70's 318 make all of what? 160 HP...? 260 ish ft lbs?
150 net. 230 gross. People do this all the time. they quote one motor in gross (your 375 hp motor example), and then use the net on the teen.