my buddy mike cut down my truck pan for me today, and i wanted to show it off, and also toss in mikes quotes on his process

"Lots of questions so....
Cut level with filter
Add 1/8" plate
Use roloc disks to take oxidation off casting, continue with 2+2 and a stainless wire brush
Preheat whole thing with torch (leaches oil out of casting) wipe with 2+ 2
Repeat as necessary
Weld using 4043 and have fun with the porous housing and oil impregnation"