best mechanical pump for high hp small block

has anyone used the race pumps they look pretty cool :D

Again, I think it would be the best choice for your application because of the port sizes. It's basically exactly what you're looking for. IMO, the Carter, Holley or Edelbrock would be marginal since the general application for those pumps is usually for a hot street machine, like around 400-450 hp. Once you're past that, you probably want to start thinking about a -8 delivery system and possibly a return so you're beyond the intended usage of a street-style mechanical pump.