Advice on Oil/Filter for 74/302/efi

[lasmitty]

I'm wanting to do a full oil/filter change on a 74 that I purchased about 3 months ago. It has a 302 with a FiTech EfI installed. I live in southern California, so the weather is temperate most of the year.

I decided to top off the fluids about a month ago as it desparetly needed some transmission oil. At the time I also added about a quart of Mobile 1 10w30. Since then I've noticed that the oil pressure at start is high, in the 90 range, but falls back into the normal range after driving a few minutes.

Can someone suggest a good oil and filter for the oil change. I plan on doing it myself. I've read lots of posts about zinc, rotella, additives etc and my head is swimming.

Thanks.

[Tom Dummer]

We've been using 5-30 for what the motor originally required. And the higher end filter doesn't hurt either

[DirtDonk]

I'm not sure every flat-tappet cam equipped engine will need it for certain, but I don't like taking a chance with the low-zinc component oils anymore. Just too many stories of wiped out cams even long after break-in. So yes, any oil you want, as long as it says specifically high-zinc content or specifically formulated for older engines with flat-tappet cams.
As for weight, I'm not much of a judge because I ran 20w/50 in mine for 25 years and roughly 175k miles. Most consider that too thick, but it worked without complaint and it kept a steady 70psi when cold and 45-70 when hot. Just what the factory expects. Didn't use much either.
Not sure why yours is going so high at first, but it could be the gauge itself, the sending unit, the IVR, or the pump's pressure regulating valve is sticking.
How are the fuel and temp gauges reading? If they're all high, suspect the IVR (instrument voltage regulator). If just the oil, then it could be the sending unit or the relief valve or the filter. Easy enough to check the sending unit or change the filter. You can verify the gauge's readings with a second gauge.

With modern oils, I'd say use a 10w/40 in moderate weather, or a 20w/40 if in a warmer climate. You can change for different seasons if you want, but I never did. Around here it's pretty moderate, with temps not going real cold for very long in the winter, and not going super hot for very long in the summer.
Nothing inherently wrong with the 5w/30 Tom is using, but many owners have reported low oil pressure when hot and erratic readings on the gauges in their Bronco engines. Guessing it's an "age related" kind of thing, but it could be other things.
Since you're experiencing high pressure, you could use the thinner oil in hopes to bring it down, but I would not worry overmuch about 90psi either. Some older cars used to run that from the factory. Not many, but some.

Just make sure it's got the goods. High ZDDP/Zinc content like in "old car" rated oils, or diesel rated oils.
There... I made it almost all the way through a post without talking about "snake oils" for helping certain things. But I just can't do it, since my own experiences with oil-additives have been nothing but positive. If you know your engine is older, and may not be in perfect shape, you can often clear up oil pressure and usage issues with one of the solvent based additives that is supposed to clean up internals, quiet noisy lifters, and perform all sorts of miracles of modern technology.
How many miles on the engine? And do you know it's history? If I was just buying a high mileage 302 I would probably pop a valve cover off to make sure that there was not a large buildup of sludge that could get into the engine, then run some solvents through it for two or three oil change cycles. Each time making sure they were still compatible with flat-tappet cams.
If that didn't make things better, then either put up with the high pressure until it's time for a rebuild, or dig into it and find out what's going on. Could be as simple as a sending unit though, so don't start pulling things apart until you check that out first.

Good luck. I say your oil weight choice is good. You've got other things to figure out.
And just need the zinc.

Paul

[Tom Dummer]

As an aside to my own oil changes. I use diesel grade oil in everything. Mostly because I want one grade of oil stacked in my garage.
But I am not one to follow the lead on this as my Bronco gets less than regular oil changes. (Sometimes more than a year apart)

[TonyNokes]

I use PureOne filters and 10w-30 Mobil One oil.
If you really want to dig into oil visit "Bob is the oil guy" site more info than you could ever want on oils.

Regards, Tony

[lasmitty]

Thanks for all the advice!

[brncofan]

Been using 5w30 also and no engine issues so far.