My wife’s 97 Big Block Suburban has been sitting for at least 4-5 years after I did a head gasket change for it. Mostly due to gas prices. I am now wanting to get her registered and back on the road. Any suggestions before I fire it up? I plan on disconnecting the fuel line just before the injectors attach a hose and drain the little fuel it has in it. Then add 5 gallons of 92 octane with Seafoam additive to it and change the fuel filter. Someone told me to add some diesel fuel to the engine oil to help swell up seals. Others have said dump some Marvel Mystery Oil in the sump. Any thoughts?

 

Take out the spark plugs and spray light oil in the cylinders and try turning it over without the plugs before trying to start it..

 

Change every fluid - coolant, oil, axles, transmission, transfer case, power steering.