Just got this truck fired up after it's been sitting for a year after a engine bay fire. It's up for an oil change, if I remember correctly we put 10w30 full synthetic in it, but only drove for about a month before it caught fire, my father in law says 10w40, but I was told that was back in the 70's, what's a good weight and what should the pressure be? I only run full synthetic in all my vehicles, this truck will be no different

 

Bearing clearances don't change with age (with mileage yes, but not age)...go with the factory recommendation. One of the main reasons a lot of the new engines run lower wt viscosity is to help meet the mandated fuel mileage requirements. Personally I'd run 10w30 or 10w40 (full or syn blend) and not stew over it. Pick one, move on.

 

This truck only has 36k original miles, so not much mileage. Cool. Straight n too the point I like it. The 30w seemed to run good, and with a 352 I don't care bout gas mileage. Thanks for ur advise!

 

Be aware that the odometer reads to 99,999.9 then returns to ZERO!

 

I suggest 10w-30 or slightly heavier like 20w-50 if it's hot all the time. Even with only 36,000 miles the motor's clearances are too large to permit the use of "zero" weight oils that modern cars use for reasons of economy.
Don't let ND's pessimism bother you. My truck's odo says 50,000. ND will tell me it's really 150,000. In fact it is 350,000. How does he know anyway? A crystal ball?
Eric

 

Oh I know this truck has 36k miles, it was bought brand new back in 66 by my father in law and driven until he purchased an F250 in 1970, and it just sat in one of his garages for 45 years, until it was gifted to his grand son, he would start it every now and again to keep the fluids circulating, he also has a 68 Galaxy with 22k original miles, so I know for a FACT that the miles are true.

 

I haven't seen a full synthetic in a 20/50, I was told back in the 50's the trucks ran straight weight oil, I might be leaning more to 10/40 bc Mobil 1 make a full synthetic of it. If I remember correctly we used the Walmart super tech synthetic 10/30 last year bc the plan was clean out any sludge that may have been in there from the oil that just sat in the crankcase

 

You can (or should) certainly understand the skepticism - it's so rare for something like that to ever happen, and it was at the same time so common for unscrupulous types to "roll back" the odometer (it was standard operating procedure for used car shops.) The old timers said they did it to every vehicle they came across. Trucks especially, were meant to be used, and virtually all of them were beat like a rented mule. How about some pics? Survivors are neat to look at.

For my part I ran 10w/30 for years. Recently have switched to 15w/40 pretty much year round, reason being it has at least some phosphorous and zinc, to keep flat tappet camshafts happy. I don't drive it when the snow and ice is around too much.

 

Been using non synthetic 10-30 in both 65's, seems best suited for the climate in my area. With the flat tappets, I add a can of ZDDP with each oil change regardless of the pro's and con's.

 

I 2nd T9's use of the 15-40. I use Rotella T(triple protection), it is a diesel engine oil and has the zinc additives for flat tappets. There are two better grades from them T-5, a synthetic blend and T-6, a full synthetic also having flat tappet protection. There is some extensive threads on FTE about oils and cam and lifter wear/protection

Knowing that your miles are accurate, tho 50 yrs old, I'd consider that engine still new, hoping it was taken care of in early life. A manual says, normal oil pressure for the 352 is 35-55 psi. The tighter the engine, bearing wise, the better it would hold at Hot (180 degree) Idle. Pressure at idle say 15 psi and a crack of the throttle and back to 35-55 psi is likely normal.