[Grady Clay]

Steve,

Al brings up an important point I neglected to ask: What exhaust do you have?
If you have the ’74 and earlier exhaust, and in good condition: Great.
If you have any of the ’75-’77 emissions exhaust, get the SSI.
I recommend an OEM ‘street’ muffler so you don’t attract unwanted attention from the Grand Ducal Police.


Al’s recommendation of JE pistons needs to be done with great care.
You need to have a set of cylinders available for Nikasil plating.
You then need the ‘right’ size (diameter) new pistons and rings from JE.
You then send everything to the Nikasil plating shop with instructions as to the desired piston-to cylinder clearance.

The plating process can deliver the exact clearance and shape of the cylinder you want.
You want ’as tight as possible but not so tight that they ever seize’. A difficult trade-off.
Another issue with the JE pistons in Mahle or Kobenschmidt cylinders is the differential rate of expansion is not as matched as the Mahle Nikasil sets.
Because of this slight mis-match, the JE pistons must use slightly greater piston-to-cylinder clearance than the Mahle RS set.
This extra clearance reduces the life-span of the JE set.

The advantage of the JE pistons is you can choose the exact compression ratio you want and match the piston cut-out to your valve size.
The Mahle Nikasil 2.7 RS set only comes as 8.5:1 CR and valve relief for your 2.7 valves.
With a careful rebuild and minor machining, you can set these just above 9.0:1 CR.

EDIT:
personally, I would opt for the more expensive Mahle Nikasil 2.7 RS set.
These will outlive several (many?) future engine rebuilds with only new rings.

Best,
Grady