And 4-bolt main blocks have been known to crack easier in the mains webbing. Small journal 327 were never offered in a 4-bolt block because it just wasn't needed. How many 327's have you ever heard of that failed because they were a 2-bolt block instead of a 4-bolt block? Most of the 62-67 327s were also built using high nickel content blocks and as such have proven to be overall more durable than many of their 350 and larger descendants.
In an 010 4 bolt large journal block i would use "Main Studs" VS "Main Bolts" as its stronger and in my opinion easier on the main webbing.
In my opinion an 010 block is good for high HP with main studs and filled with Hardblok. On street or roundy round you need some better caps such as Milodon
On a small journal block, fill up to waterpump holes with Hardblok and run Milodon splayed caps and it will handle 600-650hp from a 327 turning 9000rpm
Who ever posted the other question, yes you can use the bearing spacer to put a small journal crank in a large journal block. Be AWARE that the machine shop will have to line hone the block and will need your main bearings and spacers to line hone the block and fit them to the block - makes a difference
There is less friction in a small journal crank, as to the old wise tale about revving quicker, i dont think so
They did make large journal 327 forged steel cranks, i have one