Carb advise needed.

’73 Ford (Mercury) Capri
215 Buick/Rover V8
Magnacharger 110, 60% overdrive, 4 psi at the gauge ( since the new heads )
Merlin F85 performance heads by Real Steel ( New castings).
Viper Hurricane cam 262 advertised duration / 200 at .50.
MSD 6 AL + BTM module.

LT77 5 speed tranny and 3.09:1 end ratio with Quaiffe ATB diff.
Cars weight is about 2400lb ( without me).

Without the blower I was running a Holley 390 8007 on top of this engine which appears to be to small when the blower came on so I tried a Holley 600 ( vacuum second..) and with this carb I had a sluggish throttle response, it was to big.

So I took a Holley 465 just between those two carbs in size, placed a 600 base plate mainly to get the PCV connections on the carb ( a 465 has nothing to get vacuum and PCV connected )
I also removed the choke casting and made some conversions to get a vacuum reverenced power valve like the new Holley blowercarbs has.
It has a 4150 secondary metering block with removable jets, a secondary quick change spring kit ( brown spring installed). Powervalve is 6.5

I run this combo for about a year without any problems till too much end float of one of the rotors caused me big problems. In the time the blower got repaired I bought and installed a set of the brand new Merlin F85 heads.
With the new heads I see 4 psi ( was seeing 7psi with the old std heads ) so the flow is changed and so I have to setup the carb again.

First testdrives showed me some stumbling around 4500 rpm.
So I installed this ; http://www.dynotunenitrous.com/store/Scripts/prodView.asp?idproduct=151
And I bought the 50cc accelerator pump conversion kit and the pumpcam kit with about 8 differend cams.

I need some guidelines for working with the accelerator pump cams, they have two positions and different profiles. And how about this 50cc pump kit, is it easy to found out by the LC-1 gauge if I need this.
I have not test drive it yet with the new wideband kit so I can not tell you yet what my readings are at the moment.

Regards JP.