First of all, its not "Deve's" schemes, its Bruce Child's, another Bolter that was so gracious as to document the full flow mod. The spin on filter is the mainstay for all of today's engines. They do such a good job that we can do upwards of 300,000 miles on today's engines. That is in part due to the superior cleaning quality of today's filters. That spring pressure you are talking about is an emergency valve placed there in case of a serious imbalance which, in theory, should never happen.
GM got rid of the bypass system for a reason. It filters 15% or so of the oil and you never know which 15% it is filtering. You could have unfiltered oil from the last oil change still just sitting there. All of the gunk in the bottom of your canister is also in the bottom of your oil pan. Full flow systems have much less gunk in the oil pan and all of the crankcase gases and misc dirt are filtered. 100% of it.
It is NOT my scheme, its GM's scheme. They evolved. Like I said before over and over, Bypass works. They didnt even come from GM with a filter at all. It was a dealer installed item if you wanted one. They learned the hard way from the many trashed engines before their time that they needed to re-examine their filtering and here we are with todays amazing results. Its not defend-able that bypass systems are better than full flow. But its admirable when I see stock systems that people work really hard to keep stock by changing their oil regularly and doing the maintenance required.
The new crop of admirers and owners of these vehicles are not like the old ones. They do not wish to spend their time doing maintenance. If we can preserve their trucks by doing a little preventive modification, the next generation will still have them to enjoy.
