The 300 I-6 is a strong pulling motor when it's pulling good! The other day it started to "knock". It sounded like a rod about to let loose. On my way home from work at 3:00 a.m. it bucked twice and then died. first thing i looked for was an oil trail behind the truck to confirm a "windowed" block. None. Had it towed home (behind a ford tow truck of course). started the diagnosis. conclusion was a bad timing gear set. Went to the local auto parts store to get a replacement set for $38.00.The cam gear is a "fiber" gear. The tear down went smooth. Hint: take radiator out and a/c condensor out of the way (i was able to unbolt mine and lay it on top of the intake. carefully) remove grill section. the hardest part was removing the original cam gear(168,000 miles). it broke apart with a puller, leaving the cast aluminium hub on the cam snout. after some careful prying and a lot of cussing, was able to get a puller behind the flange. The new cam gear went on with the usual difficulties "WARNING! do not tap or hit the gear with any thing!!! you will knock out the rear freeze plug" And thats a whole other cussing session. They have a tool to press the gear on there. After everything put back together, the gear is making a noise like it is out of round and hitting the front cover. probably warped it trying to tap it on there!(see warning above) I ordered a cam kit from northern auto parts. Cam, lifters, and a new timing set "all metal" for $89.99. am going to go back in and replace the the cam and lifters with the metal gears. will let you know how it turns out and the quality of the "cam kit".