Is there any way to increase the power in the 3.5L engine...I am going to go ahead and purchase the whole engine in a few days from Mercedes via my mechanic to put in my 91 SDL. Also, once i do get my new engine..which oil do you guys suggest i should start it off with? I was putting in Valvoline Synthethic DuraBlend 20W-50. Should I switch to Mobil 1 Synthetic? I've noticed that they don't have the 20W-50? Thanks in advance.

Ro