If you currently have cylinders installed on your case, look at the base of each cylinder and locate the flange at the base of the cylinder (the case/mount studs pass through holes in the flange). A narrow deck cylinder will have a plate located on top of the flange, ostensibly to spread out the mounting pressure over a great area, and reduce fatigue at the flange surface. Also, narrow deck jugs typically use a female flared nut as opposed to the std style hex nuts (9/16 and 3/4 I think) found on WCF cylinders.

Most of the E series 320's I've built are W.C.F, or wide cylinder flange cylinders.

In the event you don't pick up the jug listed here I've got a number of fresh cylinder assemblies at STD bore in chrome, some oversize in steel and others in any number of configurations. I also include a gasket set and SL or ECI pistons with each cylinder assembly if needed.

Hope this info helps.

What model Lycoming engine do these fit?

It is not me that has this cyl for sale. thanks Bill.