Going to replace the fuel filter on a GM vehicle with a 4.3L engine (S10).

Both RockAuto and Amazon list two ACDELCO filters:
GF645
GF645F

Anyone know the difference between the two?

The part number ending in F is cheaper than the non F model on Rockauto. On Amazon it is the exact opposite.

If the images are correct on Amazon, then the only difference I can see is a slight difference in how the canister is sealed at the end and the paint. Otherwise, its probably the same filter inside. Other option would be to send them to a 3rd party lab for flow/particle analysis.

Only difference I could find with the one that ends in F is Professional; Durapack
Category, the non F one does not say Durapack.

One thing they say makes it seem like Durapack means it is a bunch of filters sold in bulk..
http://www.acdelco.com/parts/filters...lter-durapack/

EDIT: Yup, the F was attached to any filter not packaged normally, I think they used to offer a discount when bought via the Durapack bulk option.

https://forums.dealersedge.com/viewtopic.php?f=3&t=8691

William,

Thanks. For an extra dollar I would but the better filter; but not pay an extra dollar for a fancy package.

Makes sense to save a dollar, the box is only going in the trash anyway.