Cool-my idea is gaining traction. I'm sure with the larger displacement the cr would be higher using the original 4.5 heads. Not sure what the volume of a 4.5 combustion chamber is but I'm sure by time the motor is stroked the CR will be pretty high. I would like to end up around 9.5.

__________________
Tony H
W111 280SE 3.5 Coupe
Manual transmission

Past cars:
Porsche 914 2.0
'64 Jaguar XKE Roadster
'57 Oval Window VW
'71 Toyota Hilux Pickup Truck-Dad bought new
'73 Toyota Celica GT