If you have a 1994 Gmc 350 5.7 silverado and you are going to do a timing check the disconnect wire(tan wire with a black stripe) the wire is under the glove box by the heater blower motor on passenger side of truck. Its not behind the wire box on left side firewall under the hood. The haynes manual says it is but its wrong. Just wanted to put this out there if you have a 1994 like me.
