I just checked and the oil filter i used on my '78 350 gasser fits my duramax...and its like 2.00 or 3.00 bucks. Why couldn't use these filters ?

cause they have no pressure relief valve and that means they could blow off.

I buy my oil filters at Murray's Discount Auto, which is a chain store, but I'm not sure if it's national or only regional. These are boxed AC-Delco filters (part #2232). They did cost only $2.99, but went up to $3.29 the last one I bought.

That's cheap, Farm+Fleet here they're $9.99.

I do believe the filter has a by-pass valve? If the filter plugs it will by-pass media and still lube the engine. The filter is going to see pump pressure no matter how it works. The relief valve should be in the pump. I will cut one open to see if GM has come up with something new. I am leaving in the morning on vacation. I will check one out when I get back. Later! Frank

I buy my oil filters at Murray's Discount Auto, which is a chain store, but I'm not sure if it's national or only regional. These are boxed AC-Delco filters (part #2232). They did cost only $2.99, but went up to $3.29 the last one I bought.
AC Delco 2232 is the correct filter for the Dmax. $3 is a great price.