I am slowly replacing parts on my '72 Cutlass with 350 ci engine and 192,000 miles on the original engine. Next up, I am replacing all of the vacuum hoses on the engine that were last replaced at least 20 years ago and that will hopefully help the rough engine idling. What size (inside diameter) hoses should I put back on. I am not sure the correct were put on last time. It appears that 7/32 " is the correct size for the hoses that hook up to the 4 ports on the distributor vacuum control switch. I have the Olds Chassis service manual, but it does not indicate hose sizes.
I have tuned the engine many times over the years using just an Actron dwell meter and Sears basic timing light. Is a vacuum gauge necessary to properly tune the engine and what is purpose of it anyway? Would it be easier to set timing if I got the timing light with adjustments? Also, I do not understand how to adjust the idle screws on the carburetor when tuning the car. I am sure a carb rebuild would make it run much better, but I was trying to see if it can be tuned up before going to that extra expense. The engine skips, even though I have replaced the plugs, distributor, rotor and points (plug wires have been on for about 20 years, but may have about 500 miles on them). I was told that the engine may have a burned valve that is causing skip. A compression test was done on it right after I got it running again a couple of years ago and all cylinders were the same -185 lbs. I think. Thanks for any feedback.

 

set your dwell meter on 6cyl. scale and set point gap at 30deg while engine is running.also put vacuum gauge on engine,17-20.timing i set at 35deg total at 2500rpms.screws at bottom of carb is set at idle(mixture screws)turn in all the way and then turn out until rpms increase and vacuum reaches its highest point.

 

Um, you mean EIGHT cyl scale, right?

 

I think he meant 7 cyl scale. He said it was skipping one cylinder... :-)