Hi folks - I just picked up a 1979 F-150 Custom with 128 thousand miles and a 351 in it that is not keeping oil pressure when it warms up. Sounds like some extensive work is in order, and I will be farming this out, (absolutely no time to do it myself), so should I rebuild or replace, and if replace, what would be your recommendation for an occasional use work truck?
Thanks!

 

VintageRider,
I don't know where you're located but, if you find some junkyard's "off the beaten path" you can sometimes find replacement engines VERY reasonably. I bought a 390 "parts" engine for my '66 for $250.oo and I'm sure that those guys would have installed it for another hundred or so.
By the way..I'm lookin' for CZ-125 parts...got any??

 

>what would be your recommendation for an occasional use work truck?
>Thanks!

Drive it. If it isn't using a qt of oil more that every 3-500 miles, just keep driving it. The well used engine can still be getting enough lubrication to do the job that you need it for.

IMHO of course





John
jowilker


66 F100s
In the still cool hours of the night,
you can hear chevys rusting away.

 

Thanks for the advice - I would prefer to keep driving it, if possible. Are there any additives I can put in that might help the situation?
Thanks!

 

[FONT COLOR="#0000ff" SIZE="3" FACE="Veranda"]
Fresh oil regularly is the best "additive". The "junkyard" motor rarely brings satisfaction. It is a rare case that it wil prove to be any better than yours. There is nothing more frustrating than changing an engine only to find it died a week later.
[/FONT]

[LINK:www.hometown.aol.com/tbeeee|http://members.aol.com/tbeeee/page/registrysig.gif]

 

There was once a song out entitled: "Cheaper to keep Her ".
If you rebuild it you know what's in it.
If you replace it, you hope you know what's in it.

dre'.

 

I agree totally. Everybody seems to have their own opinion
about what is "low oil pressure" but as long as it runs good
and doesn't foul the plugs I wouldn't worry about it either.

 

[font color=red size=3]I agree - drive it. I wouldn't worry about it unless you notice bad noises. In the meantime, save your money for a rebuild (you will eventually have to do something). I would suggest rebuilding the one you have. You know it is a decent motor with no major problems (just worn out). As was said before, if you rebuild this one, then you KNOW what you have, and it's a good time to up the compression and get a bigger cam. Very cheap upgrades, when you do them as the engine is being rebuilt.

Just a thought.

Marty[/font]

 

My '79 351M had the same deal: low oil pressure after warm up. But, it did not have any lifter noise, and burned just a little oil. I drove it this way for well over a year w/ no problems 'til I saved money for the rebuild. Then I built it as a 400 (only difference is the crank and pistons). Lots more torque w/ the 400, and I went with flat top pistons to raise compression ratio to 9:1. With the Edelbrock intake and Carter 4bbl, plus a mild Comp Cams Hi Energy 260 cam, it now has way more torque than I'll ever use. But, it is still very reliable and purrs at idle. God I love my Bronco.

I tried the RESTORE oil additive in my 351M, but it did not help. Once it warmed up, low oil pressure. Again, I never heard the lifters, ever. Good luck!