Engine Pro's Help please

I was using a 750 on my 360 with a lot of custom tuning done to it. I then went to a ported 750 with an 850 base plate and the car picked up some. I then went to a worked 850 Demon that flows about 990 cfm. The performance and MPH picked up but amazingly enough the driveability and low speed characteristics improved dramatically. The car was easier to stage and drive through the pits.