I am now in the process of building two 340's and have already installed a tensioner on one of my engines. If you have noticed, the original cam plate has "four " bolt holes in it, I went ahead and drilled the forth hole in the new tensioner so I could install that forth bolt. But, before I installed that forth bolt, I had the Machine Shop I use drill a 1/8" hole through that bolt so some oil could seep through it to the chain. I read this idea in an old Mopar Muscle mag. a few years back. Just info. you might like.