I just bought a 1996 Chevy Silverado 5.7L V8 and it has not been started in a year until today, it was out of gas so i put 2 gallons in, and it was puffing out white smoke today, didnt puff out more when i rev'ed it. solid puff, Is this anything i should be concerned about or does it just need to run and be driven? Thanks, oh and it runs so smooth and great, no misfire.