Any tips to get more air from blower motor?

[BruthaMan]

One thing I've noticed in the Texas heat, after restoration, is that I'm getting very poor air flow through the heating/ac ducts.

We recently stripped out the cab to do some additional work and install a new deck head unit and went ahead and checked all the connections of the duct work.

Even took felt with strong tape on the reverse side, to double seal the duct work. Double checked that the "flaps" were opening when changing from heat to vent to AC, no problem there.

It has a new blower motor. I read a thread here on the forum that someone suggested getting a blower motor for a 95 extended cab. We tried that, taking the new blower motor out for a trip to Orielly's. The blower motors looked identical and we hooked both up to a battery there and there was noticeable appreciation in blower speed between the two.

Any tips for getting more air flow? Are there any "super" blower motors out there that can send a decent flow? Right now, high is maybe the equivalent of the lowest setting on a newer car. It's steady, it's cold, but the flow is so minimal that it really doesn't cool the cab very much.