I did the same thing to my 305, and could not get it out untill I had pulled the engine. Three taps on the lower half of the dipstick tube( that leads into the block keeping the stick away from the crank!) popped that little busted section out! I just used the busted half of the dipstick tube with the dipstick still in it to check the oil. Worked ok and even stayed in place ok. I was always worried about water getting in though.
Good luck with that 3.8 those aluminum heads are notorious for blowing head gaskets and warping.
|