low compression - time for a rebuild?

[coonhunter]

So my thing has had some poor performance here lately, as well as burning a little oil, so I decided to check my compression. I don't really know the history on the engine, it has always run acceptable, so I have never really done much to it, just oil changes, valves and timing checks. This is what I found:

#1 80psi
#2 74psi
#3 70psi
#4 71psi

I thought these numbers were unusually low, so I took the gauge home and put it on my bug and got 100psi, so I know the gauge is working. The engine starts with just a bump of the key and idles great. Should I look into anything else before diving into a rebuild?

[Pruneman99]

Try a leakdown test before tearing it apart. That will let you know if it is in the heads or rings. May just need a fresh up on the heads and you might be able to leave the rest alone. But if it has umpteen miles on it, it might be time for an overhaul.

[PumaVW79]

In this preview of the Tom Wilson's book there are lot of pages of the chapter "Time to rebuild?", it is worth reading.

I've read the whole book before my engine rebuild.