What you oil weight guys using with 200,000 + miles?

I got my truck with 223XXX miles on it and I am doing the first oil change. I just want to know what weight oil I should be using on mine. And it does leak from the rear main seal a little. I have had the truck for a month now and the dip stick is full. I have a 1993 B2200 Carb.
thanks

sorry for the retarded thread title I am at work lol

10w30 Just fill the oil and check the gas each week lol

I have 195K on my B2200, 12K since I rebuilt the engine (just about all except crankshaft, main bearings, and oil pump). I'm in Arizona, so I use 40 straight weight year-round, typically Valvoline when I can find it.

i live in south Florida...I think maybe 10w40, i should be good with the high mileage oil