So, in terms of electric power output, the blacktop engine is better. The next detail to take into consideration is reliability. The Silvertop engine contains a status for getting more reputable than the blacktop engine. The five valve head is Toyota's reward to your 4AG following the 4AGZE went away. https://sethtckqy.blogscribble.com/26806756/new-step-by-step-map-for-toyota-4age-for-sale