I just got my block bored .25mm over and I have a stock 81mm headgasket. Is it possible to just have my headgasket bored out to 81.25 or do I need to buy a 81.25mm headgasket? Its for a b16 and its an mls headgasket.

 

I would guess that you need a 81.25 but i'm wondering the same but i would just think that because if any part of the headgasket breaks off and goes into the engine not a good thing even though we're only dealing with .25 of an inch but still. Hopefully you get your question answered by somebody more knowledgeable on this.

 

I really need to know the answer to this question, Im putting the motor back together tomorrow!

 

use the stock one

 

Its .25 of a mm, not inch. If it was a quarter inch there would be huge problems.
.25mm=~.01 inch.
I would just buy a HG for .25 over.

 

+1 get one for +.25

 

Honda only sells one gasket, and it will work on standard and once over... they are fine on 81.5mm motors...

 

No ----??!?

 

yep.

 

I put a 75mm gasket on a 75.5mm and there was still 1mm all around before the gasket would hang over the bore.