I have heard that the turkey pan does limit the amount of air, and somewhere, can't remember, the gain of HP in going to a larger air cleaner was in the 20-30HP range. That is alot, but I wanted to go authentic so I am willing to suffer the loss. As to K&N offering a top filter, good question...don't know. I looked one time and could not find one. If in the future I decide I want the extra HP, I will probably just do away with the turkey pan and move to the larger filter. But for now, authentic is fine.
Jeff also, I will be using your measurements to order my cover. Thanks again.