farmall M block question for Gary Baker

[6 cylinder puller]

Gary we are in the process of rebuilding a farmall 281 block that was bored out to 4.375 which I think was done about 15 years maybe more but what I wanted to ask you was how much could we safely take on the cylinder walls to clean them up, not looking to over bore them just clean them up to put a new set of pistons in.
 

[Gary Baker]

6 cylinder puller, you need to sonic check cylinder wall thickness. You need at least .125 minimum wall thickness. Check to see how much wear you have, maybe all you need to do is rering it.