I thought I should chime in with most likely causes for your bearing failure.

Most likely it was caused by detonation, with a boosted engine even the slightest detonation will cause big end bearing failure.
Detonation could have been caused by too much timing, octane rating of fuel not high enough, etc.

Or you had oil surge and a loss of oil at the pick up.

The harmonic balancer is very important and I believe you should keep it.
This is why I designed my own 36-1 trigger wheel that bolts to the front of the crank pulley, allowing you to keep the harmonic and can be installed with little trouble.

pm me if you are interested in one.

As for the twin cam engine I would not use it for a boosted application.

The comps are too high. If you use one I would get a thick head gasket made to lower the comps or use dished pistons.
Ideally you want comps around 7.5-8:1, as I'm sure you already know.
Thanks.