chevy 4.3

[Digital2k2]

Hey everyone, I did a search but didn't come up with anything so here's my question:

why did chevy change the oil filter for the 4.3 from ST3980 to ST3387A in 99?

does the 3980 have the same psi bypass valve? and if so could I use that instead of the almost two inches shorter 3387A on a 04 silverado?

 

[Slick 55]

My 99 4.3 came with and recommends the longer filter.

 

[FL-400S]

The 3387A is mostly for cars (3.1L malibu I have) but Im gonna run a 3980 on it on the next change. I think they are pretty much interchangeable. You can look up the wix bypass values for both at www.wixfilters.com

 

[Digital2k2]

"My 99 4.3 came with and recommends the longer filter."

reason I thought they changed it in 99 is because the filter reference book in walmart changed from the big to the small one for the 99 and up,.

wixfilters.com says: "By-Pass Valve Setting-PSI: None " for both their filters that should be the same size as the two mentioned above... hmm, wonder if these engines have an internal bypass system?

so I guess these two filters are the same except for the approx. 2" more in filter length?

 

[ZR2RANDO]

I have a 95 s10 Blazer and a 99 s10 ZR2 truck. Both have the remote located oil filter. I use the ST3980 on both, as long as you have room for it there is no need to use the smaller filter. The Chevrolet has a bypass built into the filter mount, so the filter itself does not have one internally.
Sometimes the filter cross ref books will show a smaller version of a filter for a vehicle when they showed a larger version in the past, looks they are just using a common (smaller) size across multiple vehicles when the larger size could still be used in some of them.