Re: Car troubles
Just a few things first.
The EF/L BBM makes a Big torque improvement down low, and as you know, in some cases, bigger aftermarket cams can make your car loose out down low… probably the difference your seeing.
Also, your head work involved the removal of the chamber swirl. This swirl is used to improve torque, but obviously sacrifices top end power as a result. By removing it, the compression of your engine was also reduced as you didn't use a thinner gasket to help bump it back up.
If I were you I'd be checking things like ignition timing, and as mentioned above, comp testes etc.
Worst case, put it on the dyno again... it could just be that you are used to the thing, or the hot days my be slowing it down.
Oh, and the black smoke on start up is excess fuel. Oil burns white.
CAUTION: Slippery When BOOSTING!