how badly does a bhg affect hp because i drove it with a bhg and it seemed like it had some punch but now that i know it has a bhg or a cracked head how much hp do you think i was loosing with this problem. im thinking it is a pretty good amount.

If you are getting coolant contamination in the oil, it might not be too long before you lose ALL your horsepower. Bearing shells really don't like the coolant, but it certainly like the metals on bearing shells.

If you know that you have a failed head gasket, plan on changing it ASAP.