Sounds like a personal problem, but yeah my dipstick on this '73 240z sits very, very loose and I'm pretty sure it leaks oil when running. Been wondering if the previous owner put in wrong dipstick. 

I found an old thread that says the part number should show E3002, which mine does. (pics)

 

But, Zstore shows a 240z dipstick with P6502 stamped. Link

Anyone dealt with a very loose E3002 dipstick?

I wrapped electrical tape around my E dipstick for my 240 until I found a better one.

There's definitely a difference in a 280 vs 240. I was overfilling the 2.4 when I had a 2.8 stick in the block.

Found a good thread on this.

 

That's the one I read, but I missed the part down below about P6502 effectively replacing E3002 now, even though they obviously aren't exact matches. 

At any rate, I recall now that there was some remnant electrician's tape-looking stuff around the stopper when I checked the oil before buying. I guess that was his fix. I just applied the same fix. Sitting snug right now. Thanks. 

Try using electrical heat-shrink tubing, I did. Works fine.

Cheers, Mike