Copper ring inserts in block... okay to leave or remove?

Any issues with leaving copper ring inserts in a block instead of decking block to remove? Pros/Cons?

If the copper rings are left in the block, do you have to use a copper head gasket?

Take a close look at those rings. I know they "o-ring" the top of the cylinders for high compression/blower/turbo + some head gaskets come with O-rings for the same reason. If they are solid, I would be inclined to leave them & just do a "skim cut" on deck to clean it up.

I am NOT an expert on this, so maybe an engine builder will chime in.

We o-ringed for nitrous back in the day.

Not the same issue but I had a set of small block 915 heads that were cut for O-rings and I just used blue Fel-Pro's with no problems

Take the o-rings out and fill the groove with JB weld and file it down flat.

Sometimes the groove are just too close to the fire ring to let it go. Better to fill the groove.


Cooler may be soft (it is) but you can only compress it so far. It will hold the head off the deck.

I know guys have run the way you are wanting to do it, and they may have been lucky. I'd never run the o-rings without receiver grooves in the head and copper gaskets. And I use stainless steel wire, not copper.