Cat has put a lot of work into filter design and media materials. The 1R-0749 fuel filter is the right PN and is the highest efficiency particle remover Cat makes for this C12 application. There are three filter fuel efficiency levels that Cat produces, standard efficiency, advanced high efficiency, and ultra high efficiency. Your Beaver manual may be old enough to have the standard efficiency filter PN being specified, so if it does, you should notate the 1R-0749 as the correct version.
The Cat studies have found that the 5 micron and above particle sizes are the most damaging and cause fuel system components wear. Cat reduced the particle size distribution that they were effectively trying to capture with the new filter media in the advanced high efficiency and ultra high efficiency filters. The Cat 1R-0749 captures 98%+ of 2 micron particles and 74 out of 75 particles in the 5 to 10 micron range. The ultra high efficiency versions tend to be used for scrubbing contaminated fuel and may plug to quickly so they are not generally recommended.
There is a Beta number for filters that describes how effective they are at removing particles of a certain size. If a filter is rated at 2 microns but does not have a beta number then you have no idea if it captures 1 out of a 1000 - 2micron particles or 98 out of 100. 1 particle out of 200 passing through the filter would be a beta of 200, 4 particles out of 200 would be a beta of 50 so the higher the beta number the better. The Cat 1R-0749 has a Beta number of 75 at 2 microns and will allow 1 out of 75 to pass through into the fuel system. Just a micron size rating alone is meaningless. If Baldwin or any other manufacturer does not document a Beta number be very wary.
Nice Beta vs Efficiency Chart from Fleetguard
β 2 5 10 20 30 50 75 100 200 1000
Efficiency % 50 80 90 95 96.6 98 98.67 99 99.5 99.9
You also have no idea when you fuel up if you have 100,000- 2 micron particles per gallon of fuel or 10 -2 micron particles per gallon. In the size range of 5 microns and less I would think our fuel unfiltered has very large quantities of particles and varies a lot by supplier, age of tanks, etc. The fuel typically gets multiple passes through the filter which continues to scrub the fuel.
In Cat studies comparing competitive fuel filters, there was 45% less fuel system component wear with a Cat high efficiency fuel filter then the next best fuel filter competitor, which was Donaldson. This is probably one of the most significant easy things you can do to extend the life of your Cat fuel system components by just using the right Cat advanced high efficiency fuel filter.
When it comes to oil filters Cat also has standard, high efficiency, and ultra high efficiency filters. The Cat 1R-1808 is the high efficiency version which is also a great choice for the C12 and may not be the one listed in your Beaver Manual so while you are at it notate that number. The cost difference in filters between Cat and others is trivial in the scheme of things. Hope this helps.
Later Ed