Head gasket size vs bore

Hi i have an s54 bmw engine which i have had sleeves installed in which has brought the bore size down to 85mm. Most head gaskets for the s54 engine come 87.5mm, will this cause a problem?

Going to depend on what you're doing with the engine - it certainly isn't the preferred state but may serve you well enough.

The stock engine is 87mm bore, is the 87.5 cited the actual gasket bore or the bore size it is designed to work with, as that may be a greater gasket bore.

I assume the sleeving is part of a forced induction build, if so, perhaps you could contact Vulcan, Athena, or some of the other companies that are gasket specialists as there are multi-part solutions that use a main gasket for the water and oil sealing but separate sealing rings that inserted for the cylinder sealing - they may be able to supply, or custom machine, a suitable solution for you.

Search for "cut ring", "Cooper ring", or "Wills ring".