Top End Gasket Kit

This cylinder base gasket fits both front and rear cylinders with a 3.9" bore.

It is specifically developed for:

• Evolution Big Twin 84-99 (does not fit Twin Cam) with 3.9" Big Bore cylinders
• XL 86-22 with 3.9" Big Bore cylinders

This is a "Type A" gasket.

There are two types of cylinder base gaskets for Evolution models:

• Type A: it was introduced on the 1984 Evolution Big Twin models; it can be used on all of the 84-99 1340cc Evolution models and follows the contours of the cylinder base perfectly. This gasket fits also 86-22 Evolution XL even if sticking out at the cylinder base. Silicone beaded base gaskets may have issues because of this.

• Type B: it introduced on Evolution XL Sportster models in 1986; it fits all Evolution XL models, but also all 84-99 Evolution 1340cc models although the Big Twin cylinder base is a bit larger than the gasket. The 'type B' is the only gasket type that the OE manufacturer supplied from 1986 onwards for both Evolution Big Twin and Evolution XL Sportster models. 

Both type 'A' and type 'B' have identical inner bore diameter, oil hole and stud hole locations. Gaskets for front and rear cylinder are identical. The only difference between the 'A' and 'B' gaskets is the outside perimeter.

Athena supplies the widest range of spare replacement gaskets available on the market. Athena gaskets re the fruit of over forty years of experience in the sector, solid know-how and advanced technical skills in design and production. Athena praises a continuous technological development, achieved by its in-house team of engineers and designers, and production that keeps strictly to parameters required by OEMs.