I have a 383 stroker engine in my ElCoolmino, getting run on and backfire …

[mattfranklin]

Also, if you have combustion chamber deposits that can build up over time, you can clean them up with a bottle of Techron Concentrate (sold by my employer) used at the right dosage. One bottle ounce per gallon of tank, 20oz for a 20gal tank. Drive normally. Stop and go driving is fine. You don't need to blast it out with WOT runs.