[DAVID GAGNARD]

Troy;

A 750 cfm is on the "high" side for a 351-W like yours,but I would not think it would hurt top rpm or hinder it.... When you say it "drops off sharply at 5200" do you mean the motor "noses" over or just does it quit accelerating????? May be the valves,more so the valve spring pressure..... If you do not have enough valve spring pressure the valves will float at a set rpm and the car just plain quits pulling....trust me,I know, I did it building my motor,would not rev past 4800rpm,read the valve spring pressure wrong and did not have enough....Reset valve spring pressures to 125 lbs. on the seat and now my 484 lift cam will rev to 6500rpms with no problem....

With your cam and setup 6500 rpms should not be a problem,that's why I would look at the vavle spring pressures....

Just my .02 cents...

David