72 C10 for my 25th wedding anniversary

[MDPotter]

Oh no, a Ford part on a Chevy! Clean work on the install though, looks factory.

I wouldn't expect the pinion nut to be gorilla tight after a lot of miles, but not loose like you mentioned. When replacing the pinion bearings and races, usually a new crush sleeve is installed which takes a huge amount of torque on the pinion nut to get to the 12-15 in/lbs of rotational torque on the pinion itself. That nut is manufactured to not just thread on with your fingers though, it's somewhat of a locking nut.

I'm that the BP kit includes the 3-relay fan setup? I think the two-speed fan setup is the best if you have 2-speed fans. My SPAL fans aren't intended for two-speed so I either have one or two fans running full speed.