Compare the Pontiac Firebird Sprint 3.8L - [1967] vs Mercedes SL Class 560SL V8 R107 - [1986]. Find out which car is the fastest, most powerful, lightest or has the biggest engine in our top trumps style comparison page. Find out which car has the highest top speed or is the fastest accelerating, is it the Pontiac Firebird Sprint 3.8L or the Mercedes SL Class 560SL V8 R107. We'll leave it up to you to decide which is your favourite.