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64-67 Expert
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My '65 389 holds 6 quarts with the filter. Original pan and dipstick. My '67 GTO holds 7 quarts with filter. Original pan and dipstick. I use the long Wix filters and Shell Rotella 15/40 diesel spec oil, and have since about 2002. Prior to that, it was Kendall 10-30, no longer available. Run a high zinc/phosphorus oil like the diesel spec stuff, or the classic car stuff. Racing oil does not have the additive package needed for stop and go street use, nor the anti-corrosives. It's made to be run hard at the track and dumped.
If I were in a colder climate, I would run more expensive 10-30 high zinc boutique oil like Brad Penn. As hot as it is where I am, however, the 15/40 has been just fine. Many folks like to specify really heavy 20/50 oil, but for an engine that's set up to stock specs and not worn out, it's a bit thick.
I don't run synthetic oils in any of my old cars, and haven't in the 40+ years I've been driving them.
 

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64-67 Expert
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8,764 Posts
Hi Jim. My '65 and '67's both have their original pans and dipsticks. As you know, I've had both cars 40 years. I have never thought about comparing dipsticks between the '65 389 and '67 400, but now you have me curious if they are even the same length. Here's a couple of shots from the original owner's manual from my '67, verifying the 7 quart fill. The 389 in my '65 does not take 7 quarts. I think it's 6 with filter. Brown Rectangle Textile Purple Pink
Font Material property Parallel Paper Number
 

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64-67 Expert
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8,764 Posts
I just changed the oil in both goats and at my rate of driving, it'll likely be two years before the next oil changes. But now I'm curious. Not curious enough to drain new oil, but will keep this in mind next time around during the initial fill. As I stated, both of my GTO's have original GTO engines (the '67 is born-with) with original pans, etc. So no monkey business with mis-matched parts and dipsticks, etc. Both engines have been overhauled one time each, by me, back in the 1980's.
 

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64-67 Expert
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8,764 Posts
OK Jim....I checked both my dipsticks and here's the skinny: the '65 389 is 25" long from tip to ferrule, and the tube runs up along the valve cover. It says "Capacity 5 Qts. Do Not Overfill". The '67 does NOT run up along the valve cover....rather it comes out of the block and the loop is at the top of the head. So the tube is much shorter. The 400 dipstick is 17" long from tip to ferrule, and it says "Capacity 6 quarts Do Not Overfill"
So the '65 takes 6 quarts with the long filter or a bit more, and the '67 takes an additional quart. Both engines are non AC and have original dipsticks and pans from day one.
Swapping dipsticks would show nothing since the tubes are 8" different in length.
 

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64-67 Expert
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8,764 Posts
Hmmm. Where is the Full mark on the '65 dipstick if you marked a point 8" lower (at 17") to equal that of the '67 and then measured from that point to the Full mark. Do the Full lines now match up or is the '67 Full mark a quart higher (using the space/distance between Add and Full to determine the extra qt?).

How about from the base/tip of the sticks to the Full mark. The same distance?
The distance from the tip of the dipstick to the 'full' mark varies by 1/2 inch. Interesting. Here's photos.
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Wood Bottle Flooring Wood stain Rectangle
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