I know the difference between PI and NPI 5.4,my question is are there any casting differeces between the NVH and non NVH motors. I know around 03 they swithed over but not exactly sure when. I know when they did the new NVH block they also got more spark plug threads. I know phill had an 03 and did not have the good heads. Was there some NVH block that did not have the fixed head thread heads? Is there any casting marks that would give away if it was a good one or not like the NPI and PI heads? I found a junk yard 03 5.4 for around $1,400 with around 90.000 miles on it.

Thanks

 

I've asked about that as well. I don't know, but there has to be casting #'s on the heads to identify.

If the engine is out of an late 03 model ( after July 03), your chance are good. Updates are usually mid year , unless it's a safety update. Check the door jam if the engine is still in the truck or the doners present.

 

I know I have seen on other auto parts from the factory they have a date stamped into them, I looks like a retarded clock. My bro got a rear for his SD and it was still on the truck so I might me in luck.

Thanks jbrew.