I've done everything under the sun but the side fillers. And I think those won't help much. Two or three years now since I went to a four core, from the stock three. That helped with delaying it getting hot. Gapped the impeller and divider last year. That helped some, and the Water Wetter didn't do diddly.
Just did some reading, and found I'd better check things. Seems I have the early '69 pump (4"), so the Kooler pump is not an option. Unless I change the pullys, but I'm not shellin' out $400 for that.