that may be where i got my idea it may be [related to] a GM part. wonder if the id/od of either is close or matches ? i just measured a locking GM dipstick tube and it's .610 od. the rubber seal pressed on the tube is .795od. and .650 long to top flange of seal with a smooth[not ribbed] finish. this is a new locking replacement tube for multiple transmissions and applications i bought at a swap meet several years ago to disassemble and modify the locking part for a 727 tube and stick. i only paid ~ $1.50-2.00 for it. figured i couldn't go wrong for that price. i didn't have a mopar tube handy to measure. how do they compare ?