Greetings! Believe this is my first forum post about a car that I have been around for all 42 years of my life. My father bought this 74 GTS brand new from the Lincoln mercury dealer 49 years ago. Five years ago he had the car repainted and the engine “gone over”.
The old girl is now under my care and I am working to get her running correctly. Currently she will overheat after a long time of just idling. I’ve done everything recommended in the forums to address with the exception of adjusting the timing or see if she is running too lean. At speed the temperature is fine, it’s only when she is not moving that I tend to start having issues. I also had an engine builder buddy of mine said he could hear the car pinging a bit and detonating under load from behind. It is extremely hard for me to hear it in the cabin given how loud she is. I can also feel the car slightly stumble on initial throttle tip in when I stab it. Idle warm is 1050-1075. At initial cold start she will sit at 2100 for a minute and then climbs up to 2600 and she will then begin to slowly drop back down.
I have been running 93 and my engine builder buddy believes the car may need to run race gas to fix the issues (pinging/detonation/idle sound). I am also leaning towards making some adjustments on the dizzy to retarded a couple degrees on my own.
A couple of questions for this extremely knowledgeable group:
-Given the work below that was done to the engine, should 93 be more than sufficient or would I need race gas or octane booster?
-Given the symptoms I have explained above is there anything else I should be checking?
-Interested in this groups thoughts around what was done to the engine. Rough idea on power gains how she would drive and any trade-offs? Goal was to keep her as stock(ish) as possible, but update the engine with new components and improved performance. make her good for the next 50 years.
Also included a picture of my dad and I that is on my office desk from the mid 80s of the same car