The 4.0 Whipple COPO's had a nightmare of a time.
They get about 2 to 6 passes and the Head gaskets need to be replaced. (Due to them sending out 4 bolt heads on the motors. (THIS IS "IMO")
The good news for them is, a set of 6 bolt heads has been approved by NHRA. At this point the problem should be fixed.
