I had this happen last month on my 83 2.3L when rebuilding the block.
The dipstick tube sheared with the bottom ~5/8" still in the block. I was able to easily retrieve the other end (I turned the block over
Without the dipstick tube I noticed it took 8-9 seconds to build oil pressure as apposed to 3-5 seconds.
Also, the dipstick tube leaked profusely, enough the vehicle couldn't be driven until fixed (no a cork didn't work I tried)
My dipstick is located on the rear rear half the motor, driver side, and the top of the dipstick tube sat right near the bottom of the intake manifold.
I couldn't find a direct replacement for mine. But after a day at the junkyard with my broken tube I determined the old 2.0L Ford Courier dipstick tube had the same diameter, and same LOWER length (MUST be same to get accurate reading). I pushed it right in and haven't had a problem since.
I purchased another dipstick and tube for another 2.3L and have it on the shelf if you need it!