Oil dipstick is always sticking out a bit

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1971 Mustang Mach 1 M code 351 4 speed
You could have quite a bit of piston blow by and it is pressurizing the inside of the engine. That pressure has to go somewhere, so it is just going out the dipstick. Check that your PCV valve is installed and working correctly. If the PCV has been removed or it is stuck closed you will get enough pressure inside the crankcase to push the dipstick out.
 
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1972 Grabber Blue Mach One 351 Q code orig 4 speed. Now: 427C Titus
In addition to the pcv valve as mentioned by 71ProjectJunk, ensure the valve cover baffling, breathers and related hoses are clear and not obstructed. If all that is good, run a leakdown test. Do you get any oil spray out of the dip stick tube?
 
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no, no spray it just pops up a tad. Leak down test??? Valve cover baffling is in the inside of the cover, correct? All else should be clear. Will put in a new PCV valve first off.
 
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Just pull the valve cover breather hoses and rubber grommets from top of the valve covers and look down there with a flashlight insuring the baffling is not damaged or bent "shut".
Secondly, with the breather hoses still removed, idle the engine till warm to burn off possible condensation DO NOT rev the engine-oil may spray out at higher then idle rpm's. After warmed up observe if any smoke or oil vapor is exiting the valve cover holes. If yes, time for compression and leakdown tests which measure internal engine condition sealing health.
 
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You have received a lot of great suggestions already. I would, as already mentioned, check the PCV system closely. Starting with the PCV valve, the PCV hose from the valve to the rear of the carburetor and the hose from the oil cap on the rear of the right side valve cover, up to the crankcase emissions filter inside the air cleaner housing. I have seen those hoses collapse and occasionally have done so internally with no visible signs from the outside. All engines are going to exhibit some blow-by to some extent. If the PCV system isn't functioning properly, you will experience front and rear crank seal leakage. Ask me how I know!
And my true story goes like this. Glad to see someone else besides me has experienced "Dipstick Syndrome"! I had always heard size matters, so when I was offered a 4bl carburetor from a 428 Police Interceptor to install on my 71 "M," I jumped right on it. My original setup had a hose from the PCV valve in the L/F valve cover to a stub on the rear of the carb. The 428 P/I carburetors didn't have that stub fitting, so I just removed the hose and valve. That's just more junk under the hood, and that's why they made regular oil filler caps, right? And that would also make me a member of the throw-away club like my buddies that were throwing away all those Rochester carburetors, rev limiters, and ram air housings.
It didn't take but two days, and I had oil everywhere. Oil was seeping from the front and rear crank seals and the dipstick was actually pushing out of the tube. (Usually after racing or beating it to death like I usually did) I thought the car was possessed. When one of the shop techs looked at my car and saw what I had done (I can't print everything he said), I was made to understand the words "Crankcase ventilation" and Dumb A$$"! That was many years ago, but I still should have known better. It's something I have seen many others do, but you know how that goes when it's something of yours! :)
The photo below illustrates the baffles (circled in red) Cleveland Crush had mentioned in his post.
 

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