Feel like my 440 should be faster

Your 2500 converter is for towing. Who made that decision? . That thing must be a real pig until it gets rolling. You should be running at least a 3500 for street performance. 4500 for street/strip.

Gears do not mean anything as much as the converter for launch or acceleration from a stop.

I had cars that would sizzle the tires with 323's and a higher stall converter and others that would barely want to leave with 410's and to low of a stall.

Get a good converter for that cammed big block and your eyes will open wide.