1968 340 oil capacity

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johnnycuda

johnnycuda

JohnnyCuda's 68
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So I read everywhere 5 quarts including the filter, but I just did an oil change and it’s below the full mark by more than a quart.
Is there a possibility that it has a bigger oil pan? It looks totally like the stock pan? Thx
 
4spdragtop said:
Could be wrong dipstick, OR the tube could be wrong length.
Click to expand...
Could be, but it looks correct so you’re saying it should be only 5 quarts? I’m gonna put an extra QT in. I did use a traditional oil drain pan and it was full to the brim like it had 7 quarts.
 
johnnycuda said:
Could be, but it looks correct so you’re saying it should be only 5 quarts? I’m gonna put an extra QT in. I did use a traditional oil drain pan and it was full to the brim like it had 7 quarts.
Click to expand...
 
If you want to be safe, add a 1/2 qt. and mark the dipstick.

P.S. Not a ''fan'' of the flex with no shroud in the other post. :)
 
You can adjust the dipstick by either engraving new marks after adding the 5 quarts or by shortening your tube with a small pipe cutter. If the dipstick was ever changed who know what is in there.
 
junkyardhero said:
lets see a pic of the pan and dipstick.
Click to expand...

IMG_5179.jpeg
 
Should be a number stamped in the bottom pan, but not the sump. 3 digits than are 2" tall. What does it say?
 
If it's the 394 stamped pan and the big 1qt. filter, five is correct.
When I got my car, it had the wrong tube, so it took seven quarts to get to the full mark. I got lucky and found the right tube. Now full is five quarts on the nose.
I could measure my dipstick and tube tomorrow if you like.
 
413 said:
Should be a number stamped in the bottom pan, but not the sump. 3 digits than are 2" tall. What does it say?
Click to expand...

S'cuder said:
If it's the 394 stamped pan and the big 1qt. filter, five is correct.
When I got my car, it had the wrong tube, so it took seven quarts to get to the full mark. I got lucky and found the right tube. Now full is five quarts on the nose.
I could measure my dipstick and tube tomorrow if you like.
Click to expand...
Here’s a picture.does it look the correct height? This is 5 quarts

image.jpg
 
S'cuder said:
If it's the 394 stamped pan and the big 1qt. filter, five is correct.
When I got my car, it had the wrong tube, so it took seven quarts to get to the full mark. I got lucky and found the right tube. Now full is five quarts on the nose.
I could measure my dipstick and tube tomorrow if you like.
Click to expand...
Does the dip stick come out easy enough to cut it?
 
johnnycuda said:
You mean above the k frame? Can not see that.
Click to expand...

It's on the bottom. You can't miss it.
100_0821.JPG


johnnycuda said:
Does the dip stick come out easy enough to cut it?
Click to expand...
The tube is an interference fit. Maybe the best way to take it out would be gently rocking and tugging with needle nose vise grips.

I'll get measurements for you in the morning.
 
The best way I have found to remove the dipstick, is to put something in the tube that is a close fit, like a bolt with a long shank, then clamp a Visegrips on the tube HARD, then twist and pull.
After it's out, you can fix what got roughed up, and make it round again.
However, there is no telling how much force it will take to pull it out, and once you start, you're sorta committed. Therefore, I highly recommend to not try to pull it out. It's much easier to just modify the dipstick.

No matter what, you gotta keep the oil off the crank.
> For a modest-powered streeter,
IMO; Five quarts is enough oil in any street-pan, as long as the pick-up is on the bottom and is NOT full of old valve seals and RTV sealer.

I run a 7qt Roadrace-pan; and most of the time with about 5.5qts in it, just to get the oil away from the crank. and yes, I have a hi-volume pump, and yes the stick was carefully recalibrated by physically notching it with a file.
If the oil-level gets up onto the crank, you will have problems. It's bad enough that the oil rains down onto it from above.

And finally, IMHO, you do not need anything more than 10W30. I tried heavier oils and just ended up making a mess on the pavement, when the oil-filter blew off the pad at rpm.
Just make sure that if you are running Flat Tappets that your oil has enough ZDDP in it, to prevent the lifters from going flat. When that starts, the cam is only seconds from being trash. It happens really fast.
 
AJ/FormS said:
The best way I have found to remove the dipstick, is to put something in the tube that is a close fit, like a bolt with a long shank, then clamp a Visegrips on the tube HARD, then twist and pull.
After it's out, you can fix what got roughed up, and make it round again.
However, there is no telling how much force it will take to pull it out, and once you start, you're sorta committed. Therefore, I highly recommend to not try to pull it out. It's much easier to just modify the dipstick.

No matter what, you gotta keep the oil off the crank.
> For a modest-powered streeter,
IMO; Five quarts is enough oil in any street-pan, as long as the pick-up is on the bottom and is NOT full of old valve seals and RTV sealer.

I run a 7qt Roadrace-pan; and most of the time with about 5.5qts in it, just to get the oil away from the crank. and yes, I have a hi-volume pump, and yes the stick was carefully recalibrated by physically notching it with a file.
If the oil-level gets up onto the crank, you will have problems. It's bad enough that the oil rains down onto it from above.

And finally, IMHO, you do not need anything more than 10W30. I tried heavier oils and just ended up making a mess on the pavement, when the oil-filter blew off the pad at rpm.
Just make sure that if you are running Flat Tappets that your oil has enough ZDDP in it, to prevent the lifters from going flat. When that starts, the cam is only seconds from being trash. It happens really fast.
Click to expand...
Thx i will add an extra 1/2 quart then mark stick with a File seems to be the majority answer.
I did add some ZDDP. I used to use 15/40 Rotella or plain old high mileage Quaker state 10/40 pretty hot here in AZ 10/40 should be fine Thx!
 
I have used same Rotella 15W/40 with Lucas zddp for years without issues. Our climate is a little different north of the 49 lol
johnnycuda said:
Thx i will add an extra 1/2 quart then mark stick with a File seems to be the majority answer.
I did add some ZDDP. I used to use 15/40 Rotella or plain old high mileage Quaker state 10/40 pretty hot here in AZ 10/40 should be fine Thx!
Click to expand...
 
4spdragtop said:
I have used same Rotella 15W/40 with Lucas zddp for years without issues. Our climate is a little different north of the 49 lol
Click to expand...
I resist the higher viscosities but I don't know why. I don't drive it in the winter anyway. :BangHead::lol:
 
Dipstick tube on my '68 340 is 6-1/2" in length from the boss on the block to its tip. I needed three hands to get a picture, so there's none coming.

Dipstick is 15-5/16" from the flare that bottoms it in the tube to the full mark.

You can measure your tube and adjust your mark higher or lower depending on its length.

Another always accurate way if you know your pan capacity is to change your oil and filter and only put in 4 qts. Run the engine for a few seconds and wait for the oil to return to the pan. Mark your dipstick for 1 qt low. Add a quart, repeat the run and drain down cycle, and make your full mark. Level ground required of course.

IMG_20240712_134559044_HDR_AE.jpg
IMG_20240712_134608573_AE.jpg
 
S'cuder said:
Dipstick tube on my '68 340 is 6-1/2" in length from the boss on the block to its tip. I needed three hands to get a picture, so there's none coming.

Dipstick is 15-5/16" from the flare that bottoms it in the tube to the full mark.

You can measure your tube and adjust your mark higher or lower depending on its length.

Another always accurate way if you know your pan capacity is to change your oil and filter and only put in 4 qts. Run the engine for a few seconds and wait for the oil to return to the pan. Mark your dipstick for 1 qt low. Add a quart, repeat the run and drain down cycle, and make your full mark. Level ground required of course.

View attachment 1716275095View attachment 1716275096
Click to expand...
Thx
 
5 Qts + filter
Long filter add another Qt
Short filter add !/2 Qt
 
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