Russ,
On the BB, the extend
Russ,
On the BB, the extenders are very short...maybe a couple of inches long, at best. The inherent problem I had with them was their poor dielectric properties. When I first started to troubleshoot my suspected ignition problems, I found that a few were acring through the sides (of the insulation). When I set the OE wire set (and extenders) to Magnacore, their concern was that the extenders barely covered the end of the spark plug...hence, the spark could arc downward under high humidity conditions. Their solution was a longer rubber boot, on the spark plug end of the wire. This solution works, though it's a bit on a pain to make sure the wire is on the plug securely.
Considering the depth of the plug hole on the 308/328 cars, I can't see how you can get away with no extenders. However, there may be a better quality extender available from Magnacore. My contact there is Steve Brown...
One item worthy of mention using the MSD ignition system...If there's any weak link/poor connection, you'll know it. You can "hear" the sparks, if your connections are not 100% secure. How do I know his??? HA!
Regards,
David