The fourth-era 4A-GE engine was developed from 1991 to 1995. It's silver cam covers with chrome lettering, hence the nickname "silver top". This engine once more functions a completely new cylinder head which uses 5 valves for each cylinder as opposed to 4. It takes advantage of Toyota's Variable Valve https://jeffreyrizrg.ageeksblog.com/38274945/detailed-notes-on-toyota-4age-blacktop-engine-for-sale