I only remember seeing one set of pictures of your latest manifold (actually, you were showing the pictures of the crack in your intake plenum) and I was wondering about this stuff at that time but didn't bring up the subject of intake maniflod length. What is the diamenter of the sceet tubing that runs from your throttle body to your plenum? 

It's 1.75".

   If the tubing is not considerably larger, imagine what the intake pulses 'see' when the TB is wide open.  In other words, the motor may be functioning at WOT as if the intake tubes are VERY long which will keep the motor from turning  high RPM. 

I do believe this is one of the current restrictions.    

When I calculated this length (and I don't remember what temp I used) I came up with something like 12" for 7500 rpm.  I think I have the calcs at work if anyone is interested.  Ed, how about a sanity check.  

That sounds about right.  From memory, I think my intake runners are about 15" to the end of the TB, and the sceet tubing adds about another 8-10 inches.  

Something's going to get changed.  Just don't know what yet.  

MAP is still low, even with no inlet tubing to the TB, so I have to conclude that the intake itself is restrictive.  I can move the TB away a few inches, and connect it to the runners via a plenum chamber, which should remove any restriction issues in the TB.  I'm already thinking of the easiest way to do this.  

Rusty (time to grill)