I recently did a thorough car wash with lots of undercarriage splash. The engine stalled during the wash and it's been running a bit rough since. It also seem to want to stall every time I stop for a red light. Any ideas what could be causing this?

1973 Dodge Charger SE 400 automatic transmission. Curb weight: 3800 lbs. All stock so far. Goal: Reliable everday driveable warmed up 400 as close to 400hp as possible, then a 470 stroker if need be. Don't protect a feminist when the collapse comes!