PYB 5/10w-30 is all the farmalls sees on our farm, grampa used nothing but PYB, and we are to keep it up for now. never a problem, oil cleans over time, not the first ten minutes.
If your consern is sludge breaking up, start with a frankenbrew.
1qt detergent oil remainder ND30, next service 1.5-2qt(s) detergent oil, and so on.
97 F250HD 7.3 320K 01 Astro 220K
93 metroXFi 94.5K
01 Impala 300K
04 RTV900R 1150hrs