I have a chevy 454 that has not run in 4 years. What should I do to it before I attempt to start it?
1st step is to drain all the 4 year old gas from the tank and refill with a few gallons of fresh fuel. If you can purge the fuel line from the gas tank up to the motor of old gas that would be best.
I would pull the spark plugs and squirt in a bit of oil in each cylinder and crank the starter will all the plugs out to be sure the motor isn’t frozen. After a couple of seconds it should spin freely.
If it has a carb it will be dry of gas and spinning the motor will help pump up some gas into the float bowls. Install the spark plugs except one. Attach the plug wire to the loose plug and place the plug on the motor head or block to make a ground connection and have someone crank the engine. You should see nice blue spark at the tip of the plug. If you can’t see a spark you’ll have to troubleshoot the ignition system. If you have a spark put the last plug in and give it a go.
With a spark you biggest issue is what damage did the 4 year old stale gas do to the fuel system. Cleaning a gunked up carb isn’t fun and might require a replacement carb. Even less fun to deal with a fouled fuel injection system. If you have spark and it won’t run then you have to troubleshoot the fuel delivery system. One trick is to put an ounce of or two of gas directly down the primaries of the carb and see if you can and cylinders to fire or backfire. Be careful but sometimes this technique works and after a couple of episodes of firing, it the motor will sputter a bit and keep running.
If you think you are getting fuel, you can smell raw gas coming out the tailpipe. Do a compression check. If you have compression the timing might be off for some reason. Can you confirm the engine was running and running well 4 years ago? If it wasn’t running then, you won’t have much luck starting it now without figuring out why.
If you are successful in getting it running change the oil immediately before doing anything else.
Uncle Turbo has pretty much covered what you should do.
If it were me however I would just make sure the battery has a charge, the oil is full and go for it.
Just because it’s what I would do doesn’t make it “right” but I haven’t been burned on this approach yet.
There’s always a first time though.