Smoking SB, Information Overload
So I've searched for threads about smoking SB's and read about a hundred postings about all kinds of things and learned a lot already. However now I'm confused about which advice actually applies to my situation. So here goes.
I have a mid 70's SB 327 in my 911. Unknown number of miles or years since its last rebuilt. Its got quite a high lift cam, edlelbrock manifold and carb, HEI distributor. The exhaust is completely seperate for each bank. On acceleration I get a big cloud of blue smoke only out the left tailpipe. There is no smoke on starting, even after sitting for a few days, there is also no smoke when I rev the engine up to about 4000rpm while in neutral. It only smokes when its loaded and driving. I did a compression test and got between 135psi and 155psi. Checked the plugs and #3 on the left side is oily and black, the rest are dry and brown. That cylinder #3 had 150psi compression.
Since it only smokes out one side, I've discounted oil getting sucked in from the PCV. And since it doesn't smoke on start-up, I think the valve seals are ok right? So I'm left with head gaskets or rings? Is there a way to confirm which it is? I'm optimistic its not rings because of the good compression test, am I right?
Cheers and thanks in advance.