I find I get the best results with Ektapan in less contemporary developers rather than more contemporary ones. I shoot it in 8x10" and I've shot some in 11x14", and I rate it at EI 50 in ABC pyro 1+1+1+7 for 10 min., targeted for contact printing on Azo, which does best with a contrastier neg.

That might produce more grain than you want for 4x5", which I assume you'll be enlarging, so you might try PMK instead. I've also tried Ektapan in D-76 and Acufine, and I find that it really responds well to pyro.