[Guy]

Our 1984 has no restriction guage, but I sure like the idea. So it gives amount of vacuum under full throttle? I have just taken a guess and changed air filter at 20 thousand miles. I thought it was overkill, but I noticed that the replacement filter was significantly light than the used filter, so maybe not. BTW, I found that using silicon paste, not silicone spray, made getting the two rubber boots back on the filter much easier.