Intercooler

[Spikesoftail]

To much fuel in the cylinders can and will cause lower compression readings. A wideband would help you get a handle on how much air/fuel your actually running though. Unfortunatly those early cars didnt have much for computer scan data, so I think thats about the only way of checking your A/F ratio. Black plugs does tell you its running rich, but how rich and at what rpm its getting rich is what you need to find out.