Running a 509 with a 177 blower, 1080 Dominator. Motor runs great and on the dyno made power to 6100-6200 rpm. The problem I'm having is: it will be running fine and at no given time when at 4500 and over it's like someone turned the key off. Does not feel like it's fuel starvation as there's no popping, backfire, studder.... it simply cuts off but if I get it to neutral fast enough it picks right back up on idle and then will run fine until the next time it happens. It happens often but at no given time where I can pin point it and make it happen at will.

Do you ever smell burning rubber? It could be your engine coupler. My 454 had similar symptoms, ran great until the rubber got hot enough to slip...

Your trying to run a 509 with a 177 blower to 6 grand????????????????????????????????????????????? ??????????????????

rig a fuel pressure gauge that you can read from the dash. It sounds to me like you are running out of fuel.

It is likley the TPS or the MAP sensor.

Yep its a defective MAP sensor on your carb, seen this several times..........

Mine just did this and it was electric fuel pump. Not sure how yours is set up. Mine has electric fuel pump, mechanical pump and vst tank.