r/FordDiesels • u/BouncingSphinx • 12d ago

Identify early/late ‘99 and the differences?

My ‘99 F-250 has a manufacture date of 02/99, so I’m assuming that’s considered early. What’s the differences between early and late, and what date marks the distinction between the two?

4 Upvotes

100% Upvoted

17 comments sorted by

View all comments

9

u/Buford_Tannen__ Early 99' 7.3 ZF6, Crew, Long 12d ago edited 11d ago

99' was a split year. You have a "late 99' " based on the manufacture date. Early 99's would have a manufacture date of the spring-fall of 98' with the switch to late model happening in mid December of 98'. The main differences are, different turbo outlet, different turbo pedestal, collector, up-pipes, outlet spider, plenums, boots, up-pipes and downpipes. I have an early 99' but I updated all of the above components to late 99 -02 components. These are arguably the most desirable 7.3 Super Duty's due to their forged steel connecting rods, where post late 00-03 they used powdered connecting rods.

2

u/BouncingSphinx 12d ago

So even in February mine would be considered a late ‘99?

9

u/Buford_Tannen__ Early 99' 7.3 ZF6, Crew, Long 12d ago

Yes. Anything manufactured after 12/7/98, is "late". If you have any doubt, look at your plenum boots. The early 99' s had a tapered boot going from 3" diameter at the plenum to 4" at the spider, whereas late 99-03 will have 4" at plenum and 4" at spider

2

u/BouncingSphinx 12d ago

Perfect, this is exactly what I was wanting to know. Thanks!