Up, up in the Air
When it comes to jetting, there's another rule of thumb that states for every 700-800-foot change in altitude, the jetting should be adjusted. Basically, this is the same thing as an increase in temperature. As altitude increases, the available air molecules in a given volume decrease. The solution? Decrease jet size as the altitude increases. Just be positive to use the same "one jet number at a time" methodology, and always double-check the spark plugs.
Little Squirt
If you know or suspect you've got a vacuum leak but can't seem to locate it, try this: Mix three parts water and one part dishwashing liquid together. Put the mixture in a toy squirt gun and squirt all the vacuum connections, one at a time. When the idle smoothes out-you've found your leak.
Header Fix
If you cut the header-to-cylinder-head flange in one or more places, between the bolt holes, it will help the flange conform to the head more evenly and reduce gasket failure. Once the bolts are tightened, retorquing them after a few heat cycles, and periodically thereafter, will extend gasket life. Tighten them when cold-not hot.
Step Up to the Pump
If your Carter AFB or AVS develops a hesitation after the car has been sitting for a while without being run, blame it on the leather accelerator pump. The material dries out, contracts, and no longer seals properly to the pump well. The fix? Install a marine application neoprene pump and the problem is gone for good.
The Distillery
If the water in your area is hard or contains lots of mineral deposits, use distilled water to fill the cooling system of your car. It will prevent deposit buildup and keep everything running cooler and longer. Use it to create the 50/50 mix of water and antifreeze, and add a can of rust inhibitor/water pump lubricant while you're at it.
Having a Seizure?
As technology and engine materials have changed, it's almost mandatory to use an antiseize compound on the spark plug threads in an aluminum head. So what's stopping you from using it on the plugs in your cast-iron heads as well? It will lubricate the threads and make the plugs a whole lot easier to remove in several thousand miles.
Bearing Down
If you suspect you have a rear axle bearing about to give up the ghost, but you're not sure which one it is, there's a simple and reliable test: If it makes noise on a right-hand turn, it's the left side gone bad. If the noise rears its ugly head on a left-hand turn, then the right side bearing needs a replacement. Some things are just too simple, eh?
Lights Out
If your taillights or backup lights are doing some weird things, and you've already checked all the wiring, then there's one thing more to check. The ground between the light's housing and the car's body may not be good enough. Scratch a little paint off where it won't show and reinstall the housing.