Trickflow trackheat or performer rpm
I’m not suggesting the OP run out and buy a RPM.
He should try what he has.
But if he feels the motor is a bit soft when he’s lugging around in 5th and 6th gear.......and is looking for improvement in that area of operation.....he might consider trying the RPM.
It’s a whole different situation than running an auto with a high stall converter.
The crossover point........where the single plane will start to surpass the dual plane will likely be in the 3500rpm range.