The 5.6 rods have a smaller big end. They have to go with the 5.6 crank. I have 3.5 heads, K jet 4.5 heads and 5.6 heads if you need pictures. I also have 3.5/4.5 and 5.6 valves if you want to see them side by side.

__________________
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