Crate 360 vs DIY Built
The benefits you get from a good engine builder are features such as head porting, establishing optimum quench, flow testing, having your heads cc'd, cam degreeing, expert selection of components, etc, etc...
The engine I ordered from Mike is the first one I've ever ordered from anyone. I chose him because of his outstanding reputation and expertise. It's been over 30 years since I'd done a complete engine assembly myself. Was it hard? No. - But I know I lacked the expertise to choose the best working combo for my builds. My engines ran fine. But there are some guys out there that seem to be able to squeeze more RELIABLE power from their builds.
Mike has competed in national engine building competitions and if you do decide to have someone put something together for you, he is very good. He has been experimenting with different combinations over the years to try to come up with recipes that work.
It's difficult to know if you're making correct component selection when you don't have as much experience. If you post questions on a site such as FABO, you'll get conflicting advice. There may be a general consensus on direction to go but I do see the benefit of having an 'expert' oversee things.
I don't regret having done my own builds in the past. - And I'd actually encourage you to try it yourself if you haven't before. But if you're looking for an engine you can drop in MRL isn't a bad choice. You aren't purchasing an off the shelf assembly line slapped together engine if you buy from him. You will be (if you want) participating in the selection of certain components to get you the amount of power in the RPM range where you want it. - Those 'crate' companies don't give you that.