I like my Lycoming 0-320 oil cap on pretty tight, for peace of mind (obviously), but sometimes it's hard to unscrew it later, especially with limited access down inside the cowling.

I made this to fit on the end of a 3/8" square drive T-handle I have, to give me better torque on the cap. it fits the dipstick cap perfectly, and grips it enough to withdraw it to check the oil level without touching it directly.

I'm not sure it will fit ALL Lycoming oil dipsticks, but it seems very similar to the one I used to have on an IO-540, so I think it will likely fit your engine.