So... we have all heard about steel guides and dual roller chain. I bought an 84 pickup. MC 470:1 in the transfer. 36" TSL. It was basicly a first second and third gear outfit. I Yukon 5:29ed it and Grizzly locked front and back. So much for background. It always sounded like it was grinding itself up when idling an I thought it odd that the crank pulley stu k out a touch. Turned out the timing chain was dual roller with steel guides. The straight side here about 3/4 " overall removed by chain slack. Timing cover was grooved bad and a pile of metal and fractured chain rollers in the oil pan along with a chunk of aluminum from the lower inner cover. Alsoa half inch piece of the straight side guide managed to make the journey to the pan.
All this to say that chain stretch; increased slack from deck and head resurfacing contributes to a repeatable event. I put stock single row and plastic / nylon guides back in. Tough motors 22r but when it happens again and 4 intakes and exhaust valves become part of the fix I think I'll go to 2rz. Sure a new head rods mains rockers an I be set. Set to get 90 some horsepower back. Not to mention $$$ to get more than stock suddenly 142 horse power stock and reliability look pretty attractive. Plus better fuel management. Enginebldr told me they tested to failure both dual and single row chains an they both broke at same tension. I've seen ads for pre-stretched chains not sure what to make of that.
