I had my primary tensioners, gear chain arms and gear chain guides replaced. Lots of chain slap on startup and once the oil warmed up to normal operating temp it made a rattle at low rpm (below 1200 rpms).
I recommend getting the metal tensioners which I discuss in this thread
http://www.mercurymarauder.net/forum...ad.php?t=92299
You'll need left & right primary metal tensioners, left & right gear chain arms, left & right chain guide arms, and a Felpro Timing Cover Gasket Set p/n 45980. Also need some new coolant of either a pre 50/50 mix or pure and mix it yourself since you'll need to drain the radiator to remove the coolant hoses.
You may also need a valve cover gasket set and new O-rings for the COT (Crossover Tube).
I had a fellow MM owner do mine, he was able to get the timing cover off without removing the COT or valve covers. He loosened the bolts on the valve covers and shimmed them enough to get the timing cover off. Also had to shave/chip part of the oil pan gasket away for more leverage.
I ordered the tensioners from RockAuto and got the gaskets and chain guide parts from Advance Auto Parts.
Time frame took about 8-10 hrs and that was moving at a slow pace since we bs' ed around, the person who did it also had done it before so it was still fresh in their head. I believe most of the timing cover bolts are 18 ft/lbs tq rate.
Before & After pics
http://www.mercurymarauder.net/forum...ad.php?t=92538
Only issues we ran into was getting the timing cover off without removing the COT/valve covers, had some oil drip down off the VC to the exhaust and smoke a bit and then needed to burp the coolant system 3-4 times since it had a lot of air in the system.