I think the extra plugs on the filter adapter are there in case you wanted to plumb an oil cooler, but you could use them for what ever you wanted to. As I said on my 87 D21 I used all 2 5/8" Autometer Sport comp gauges with mechanical senders where applicable, (working in a 4x4 shop and getting parts at cost helped quite a bit in building my hardbody), I just realized I said you could mount a tranny temp gauge but what I meant to say was an oil pressure gauge, my trans temp gauge I used the autometer manifold in the tranny cooler line.
As for the billet adapter, I don't care if it's billet or not I was just trying to find an a filter mount with the extra plugs, most of the Mr. Gasket,trans-dapt filter mounts only have an in and an out connection unless you used the dual filter mount like I have.
I know the Fram PH8a is usually the standard filter people use with these remote kits, or the K&N,purolator,etc equivalent, but I remember Fram made an even bigger filter I think it held a whole quart (maybe 2) more of oil, I remember getting one for my buddy for his 86 Toyota 4x4 as the 22R had plenty of room for a longer filter and was the same thread as the PH8a, the other benefit of using the PH8a filters are they are always on sale and are usually cheaper than the 3682 filter, (pathetic that I remember the Nissan filter number!!)
just found this, this may be the larger filter, not saying larger is better just sharing info:
Part Number PH8A
Product Type Full-Flow Lube Spin-on
Anti-Drain Valve YES
Gasket I.D. 2.42"
Gasket O.D. 2.8"
Gasket Thickness .2"
Gasket Usage Base
Product Height 5.14"
Product I.D. 3/4-16 Th'd
Product O.D. 3.8"
Relief Valve Setting PSI 12
ph977a
Anti-Drain Valve YES
Gasket I.D. 2.42"
Gasket O.D. 2.8"
Gasket Thickness .2"
Gasket Usage Base
Product Height 6.91"
Product I.D. 3/4-16 Th'd
Product O.D. 3.78"
Relief Valve Setting PSI 12