Blades Cloggs! Looking for High volume discharge blades.

I have an older MTD rider with a standard bagger system on a 38 inch mowing deck and a 12.5 hp briggs engine. It has plenty of power to do the job, but often in a little longer grass or going a little too fast or a little moister on the ground, the chute clogs. I'm looking for a blade that delivers a larger air flow up the discharge shoot to help avoid these annoying clogs. I don't mulch, just discharge or bag. I've looked into gator blades, but they are designed for mulching but do have a good air flow. Another would be the Mamba blades, but even though they are larger in width and size and deliver more air, they are designed for mulching. If a mulching blade would help get the grass up the shoot, I wouldn't be opposed to it, but their must be a blade that is designed to deliver a lot of air flow.
Anyone that has good experience with getting more air up the tube or stopping the clogging, this would be appreciated.
Thanks Rex