What main bearings for a high performance engine?

BTW, OP, the trade-off is:
- Full groove mains give better rod bearing oiling which is an area of concern of the SBM oiling design at the highest RPM's
- 1/2 groove mains makes the load on the main bearing oil film lower..... less chance of pushing it out under high pressure

That 3/4 groove set is a compromise of the 2 factors... maybe a great idea!