Do any of yall know if the early '99 trucks require a different IPR than the other 99-03's since they have the smaller HPOP? If so do you know the part number? Thanks a lot

 

This LIST says the o rings are the same. The IPR's are different as you stated. The pump #'s are listed below.

IPR O-Ring Kit (for when IPR valve replacement is not required)
(Ford) F6TZ-9C977-AN (F6TZ-9C977-AA?)
(International) 1825806C92 (1825806C91?)



IPR Injection Pressure Regulator
(Ford) F4TZ-9C968-C (engine serial no. 187099 & before or pump no. 255C92)
(International) 1824982C91 (engine serial no. 187099 & before or pump no. 255C92)
(International) 1833798C91 (All Years ???) latest part number
(Ford) F81Z-9C968-AA (engine serial no. 187100 & up or pump no. 247C91)

 

Thanks a lot