Oil Pan Order of Operations
 

Howdy folks!
86 f150 300 4spd manual 4x4
Gearing up to do my oil pan gasket, again... I'm also wanting to seafoam my engine, so I am wondering if I should seafoam first then drop the pan or the other way around? My NAPA guy advised me to not add seafoam to my oil on account of it eating old seals (I've replaced the front main, but the rear is still old) should I be worried about this? I am also noticing that my oil pressure reads in the normal range for the first cold start of the day--then drops to low on the second start. (some times if I run it long enough I can watch the needle dip.) I'm planning on testing oil pressure with an independent mechanical gauge, but I'm currently laid up from a double hernia surgery, so it'll be a little while before I get to it. If I get bad oil pressure readings what should I look for with the pan off?

Thanks!

Check bearing-to-crank clearance with plastigage (sp?).

I would not seafoam the engine either. It can knock stuff loose and clog the oil passages on a extra dirty engine.