Thanks for all your input and suggestions. One question. When i go to rebuild should i use the same cam? I plan on using the same valves and i will just clean them up.

Thanks again to all.
Cheers

 

I would not assume you can use any old parts until you inspect them thoroughly first. Lots of small things can make a new part seem a better deal.
That includes the camshaft. It "might" be perfectly fine, or it might be thrashed for the same reasons that the rings are so spent. Maybe oil changes were not the PO's first priority. Maybe it was overheated a few too many times. Just too hard to tell until you pull it apart.

But speaking from my own experiences, where I kept the stock original cams in place, I would have been better off getting a new one.
I'm not saying you should go all radical race cam on yourself, and regret that and all the changes needed to keep it working well. Just saying a new tech mild stock replacement is usually a very good thing.
And you may find that it's absolutely necessary too, once you inspect the lobes and lifter bases.

When you did the compression checks did you do it with the throttle held wide open? If not, you got skewed readings.
I agree that those are not completely unexpected numbers for a '79 perhaps. But they are still kind of weak, and certainly not as consistent as you'd like to see. The numbers actually look pretty pitiful compared to other 302's and 5.0's, but hard to say what to expect from an old tired '79. Maybe there is a listing somewhere?
Not only a wide spread, but lower then one would hope for as well. Unless tested with the throttle closed, in which case they may be perfectly normal.
One might hope for more in the 110 to 120 psi range for all cylinders, but a lot depends on not only the static compression but the cam profile as well. An earlier truck version of the 302 ('71-'72-ish) would be in the 125 range (from my own experience), with a vacuum reading at idle of 20-21 hg.
What is your ignition timing set at? If it's too retarded you will get a weak vacuum. Oh, and at what altitude are you? Vacuum signals go down as you go higher. So that 13 might be due to a few things (including bad rings of course), but it's low in any book except on a high performance engine.
Even a cammed 302 should get at least 15 at sea level. That 13 is not enough to run a vacuum brake booster.

Has the engine been sitting for a long time and you're just now starting to drive it? Old tired engines can sometimes be saved by simply driving it regularly and a couple of oil changes with a flush to clean up some of the insides. As long as sludge deposits are not expected, a good oil additive/cleaner before (and sometimes after) an oil change can do wonders.

Now back to your lack of power from another angle. Sure, the engine might be weak (the numbers kind of indicate that) but what tire size do you have? Those 3.0 gears are not very friendly to power when you have taller tires and the engine is working twice as hard to get you rolling.
A stock '79 302 is not going to be a power house no matter what, but that's just another good reason to change the cam and the timing set to get better more modern performance. They were just experimenting with emissions controlling at that point, and were still learning a lot. A few years later that same engine had half again more power.

Good luck.

Paul

 

Paul, thanks for the comments. I'm running 15" tires. I live around 6800 feet above sea level so i would expect a 10% to 20% reduction in compression and vacuum. I did the compression test with the throttle wide open. Also, i did a tune-up (new plugs, wires, coil) during the winter and when i removed the plugs for the compression test i noticed the white insulators were very clean.

If i replace the cam can someone recommend one? I see prices from $60.00 on up. I assume they are all made by the same Chinese or Mexican factory. I think the price difference is someone in the US checked the specs on the expensive ones.

Thanks

 

I'd think getting a deeper look at what is going on with your engine would be in order before picking out a new cam.