I recently went about 6 months without driving my '51 1/2 ton. ('53 235 powerglide engine with a '53 Corvette head) Bad, I know. When I went back to driving it, it would hesitate and cough on acceleration, and I though, "I need a tune up". Suffered for a few days.
When the tank was close to empty, I pulled in and filled her up with high test. within a mile, she was running smooth as silk.
Gas went bad? I'm sure of it. You may not need to drain what you have, just fill it with new and go for a long drive and fill it again.
Kurt
