Well tried putting new shells in on the off chance, no such luck. Fired up and ran for a little while fine, but when revved up it knocked again. bad times. Had literally the worst luck with everything in my life over the past few weeks... Buying a complete freshly removed 4efte to put in it, and already have a full gasket set, so i'll be taking the crank to park engineering for a regrind/polish, order a full bearing set with oversize shells (hoping to get away with only 0.25 oversize, that's if the crank isn't scrap haha). And then rebuild. Only saving grace is the piston rings, valve stem seals, headgasket are all brand new so don't have to split the block again. Just get the crank machines, bearing set to suit, and new oil pump. sigh...