Oil choice for 78 monte carlo

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Nov 7, 2010
Hello everyone..I just picked up a 78 monte carlo with a 305 in it. No leaks or burning of oil that I can see. The car has 47k original miles on it and I was wondering which oil to use and if a synthetic or synthetic blend has enough additives in it to be sufficient in that engine. Or should I just stick with a regular dyno oil? Ive read on the forum of people using Mobil 1 with good success. Any help would be very greatly appreciated..Thanks again
A bone stock 305 does not have lofty oil requirements and anything on the shelf now is better than what was available back then. I'd probably run a cheap HDEO in 10w-30.
Agreed. Nice car. I sure wish I had my two-door '78 Malibu with the 305 again. Synthetic would be a waste since a smog-era V8 would not be a good candidate for extended drains. I'd go with a decent high mileage dino, personally.
I appreciate the feedback..I was reading different posts of people saying you need an oil with a high zinc content ..Is that applicable for this engine too. I dont know much about the car since I got it last night but I wanted to change the oil and put the right one in
That's thing is well broken in so the need for lots of zinc shouldn't be an issue. That said, it couldn't hurt either.
If u recall correctly, those engines were known to wear the cam out because it wasn't flame hardened. It is a very cheap engine to rebuild and make faster.
my 92 chevy 1500 with the flat tappet cam 305 got better fuel economy and the engine was much quieter when i started running royal purple hps 5w-30. i'd recommend that.
Originally Posted By: Danno
If it was my car, I would use Pennzoil Yellow Bottle, 10W-30.
That's what i use in my 83 305 with 230K original miles although for the longest time i ran straight 30 weight Pennzoil.
The 305s I had were hard on cams & valve seals-I would add a vote for Maxlife, in 10W30 or whatever weight gives you good oil pressure (at 47K it shouldn't matter). I miss my old '78 Monte, had T-tops & a 305, totalled in a snowstorm by an idiot with no insurance (not me).
[censored] that sucks he didnt have insurance. I will put up some pics of the car as soon as I can and I apprecaite all the feedback..I will go with PYB or even a maxlife and just do regular interval changes
You're in NYC so you get decent cold in the winter. I'd prolly opt for Maxlife 5W-30. The gaskets and seals are getting long in the tooth. A little pliability will not hurt anything smile The zinc (ZDDP) requirements are something to think about. But no high zinc oil will save a bad cam. It won't even prolong the agony more than a few days. It's a metallurgy issue, not a lubrication issue ... That is the era where GM had issues with cam core softness. So it's worth looking into. The best way to do that is to pull the valve covers one at a time and fire the engine (warm after a drive) and look to make sure all the push rods are spinning at the same rate? If one is slow, or stop start, you have an issue with a lobe going flat. If they are all spinning at the same rate, and the top end is not filthy, I'd say any oil with 800 PPM of ZDDP is adequate. The valve train is well broken in and all is well smile Those are OEM springs, so there is not much load on the valve train. If you don't want to use Maxlife, a good 5W-40 HDEO would be my second choice in your climate.
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