True .060 is not nessisarily an issue , but if the bore is already at .060 now & the bores are not perfect would you risk .070 over ?
Generally you need .125 thickness on the thrust side so the outer walls of all the cylinders .
Other options include going to an R3 block but that would be a couple of thousand $$ .
I bet a machine shop would work with the cost maybe doing all 8 sleeves for $800 & 340 blocks are not that easy to get anymore ,
360 block is the simple solution you should be able to grab one for free - $100 they just have a slightly smaller bore than the 340 block