Howdy Slick folks! I have a question if I may. When I drive my 66 f250 4x4, the oil pressure will drop while taking right curves or stopping. It doesn't take much to cause the pressure to drop dramatically. I Just did my second oil change, filling it up to the mark on the dipstick, but it only took 4 quarts as a result. To my knowledge the 300 should take 5 quarts roughly. It does not lose oil pressure taking left turns, even very hard ones. A gentle right turn or deceleration will cause the needle to swing wildly and eventually go down to 5-10 psi. Thinking I should add another quart regardless and start searching for another dipstick. Anybody have a correct length 300 dipstick that I can compare my measurements to? Thanks in advance!

 

4 qts is not enough oil. Oil is running away from your pickup sump while turning and stopping. My 64 has a 292 V8 in it and even with the 6 qts in it as called for by the book, on a real hard stop it will loose oil pressure. My guess is your 6 will also take 6 qts with a filter change and 5 if no filter change. Put more oil in it.

 

Thanks for the reply. Threw another quart in last night, and I'll buy another today.

 

I'll get you some measurements from my dipstick on my 300 in a few. It's a short little dude compared to some.

Chad

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Sounds good, thanks.

 

C5TZ-6750-J - still available from Ford.

Top of shield to full - 12.52"
Top of shield to add - 13.06"
Top of shield to end - 13.82"

Those are from the book.

Also, overall length is roughly 17"



Chad

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If I search the forums on that part number I get this one with info from ND, too.

https://www.ford-trucks.com/forums/1...dip-stick.html

Chad

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If your oil pickup is the correct one for that engine you shouldn't lose pressure with 4qts of oil in the engine. Unless you're doing 4g turns. You can bet the Ford engineers tested it with less oil than that. You may have plugged up oil drain back holes in the head and filling the valve cover with all your oil. I've seen engines that those holes were so plugged that even after being hot tanked it still took a drill bit to clean them out. Or the valve train could be worn to the point that it is pumping oil to the top end faster than it can drain back. Just a thought.