Gene,
a couple random thoughts.
74' is great, congrats, keep it up.
work on improving your backcast. make sure it really is 180 degrees from your intended target.
practice picking a backcast target and hit it.
make sure you have no slack in your backcast pickup.
don't make a bunch of false cast. develop a pattern or cycle that you stick with. i try and use a pick up and get it together cast - then shoot a little on the forward cast, shoot a lot into the backcast and deliver.
loop control. continue to practice making good loops, 3' front and back, without hauling. work on balanced loops at 35-50 without a haul. the logic being if you are making good narrow loops, front and back, at those distances, adding a haul improves the line speed of a good cast.
the longer the cast the longer the stroke - short cast, short stroke, longer cast, longer stroke.
practice weight shift from your back foot to front.
look at increasing the speed of your hauling hand, rather than your rod hand.
make sure your haul acceleration matches your rod. your haul stops when you rod had stops.
look at the trajectory of you final forward cast, it should be climbing, rather than landing.
head length is important in fly line distance. I don't know what WF line you are using, but play around with a longer head in like a salmon steelhead or a triangle taper, a line can give you a longer carry and some extra distance.
use a clean fly line.
when you practice distance, pick a specific number of practice casts and then quit or work on something else.
john