Join Date: Aug 1998
Location: Waldorf Md. USA
There are a bunch of factors that come into play when deciding if a block needs align honing.
1. What type of motor are you building ? Stock, Mild street, or a 800hp blown small block ? The more HP you are making, the more important it is that all tolerances are perfect, or as close to it as possible. One of the most important reasons for the align hone dimension to be correct is so that the bearings will be held in place properly. This is called the "crush"
2. What condition was the motor in when it was disassembled ? Particularly, how did the main bearings look ? If they were barely worn, or worn slightly and very evenly, chances are the align hone is fine. If the main bearings look at all suspicious, at least get it checked.
3. Are you replacing the main bolts with studs ? If so, align honing is almost mandantory.
These are just a few of the things that go into the decision. I personally have started insisting on align honing any type of performance engine. If you are spending 7k on a motor, the $130 to align hone is a minor part of the picture. On stock motors, I play it by ear, using some of the criteria I listed above. If you check all the clearances properly when you assemble the motor, any problems will show up anyway.
By the way, "core shift" has absolutely nothing to do with align honing.
Hope this helps,
Advanced Automotive Machine
1971 Chevelle "Heavy Chevy" original owner
1973 Z-28 ..one family car...Brother bought it new in 73