Sonic Testing ( LA Blocks )

Greetings - fixing to start checking my blocks sonic testing so hopefully I have one that will work for my needs , trying to take a 318 and bore it 90ths to make 4.00 bore .
I have heard from two creditable folks who say it can be done .
I have the following blocks
2- std bore 1974 blocks
1 - 20 over 1968 block
1- 20 over 1970 block
Traditionally the older the block the better but we will see
Going to check the 68 & 70 blocks since they are not standard hopefully both are suitable for 90over bore thanks for any input.

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