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Discussion Starter · #1 ·
According to this site: http://www.1967mustang.com/toolbox.htm
the trans fluid differs for each engine with an auto trans. I don't really understand that though. If you have the same trans, why does it matter what motor you have? I'm confused. Why would the engine dictate how much fluid goes in the trans? ???
 

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There were different transmissions for the small block V8 (C4) and the big block V8 (C6). The inliner used a smaller version of the C4's torque converter, IIRC.
 

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Converter size is the one major variable within any trans family with regard to fluid capacity. Secondarily, if an aftermarket deep pan is being used (which is usually obvious).

I use an extended filter and slightly underfill, based on the dipstick. Given 8" converters and deep pans, who knows what the right capacity is anyway. Better to underfill than foam; trans doesn't run good on foam. If it takes the launch G's and doesn't release or foam, then I mark the stick and it's good to go.

Or, just trust your dipstick (Midlife) :D

Pat
 

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Discussion Starter · #4 ·
Any idea on a safe amount to start with when breaking my motor in? There's no way to get an accurate reading on the dipstick without your motor running, but I don't want to put too much in and then have it shoot out when I start the engine. On the flip side, I don't wanna put too little in and ruin my trans. The only difference in my trans from a stock C4 is the B&M 2400 stall converter.
 

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Just some guy
67 coupe, 69 Sportsroof, 86 hatchback
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Generally with a C4 you would put a quart in the converter before installing it. Did you? It's SOP at transmission shops and a good practice, though not usually absolutely necessary. With a stock C4 pan you'd want to add four more quarts. More than that and it tends to "flood" the trans and may find unexpected places to leak out. After you get the engine running, add two more quarts. At that point you'll have seven quarts in it which is plenty to get by until you can devote time to filling it up to the correct reading on the dipstick. (Assuming you will be distracted by babying the fireup of a new engine, cam break-in, etc.) If you have an aftermarket "deep" transmission pan you can increase the initial fill by a quart. Total fill will likely run from 8-8 1/2 quarts total for a stock setup. Sitting and running a quart or two low will be fine. You will want to be all the way full before the first test drive though. Total fill will be more for a deep pan and/or and external cooler, but not so much more to be a problem during engine break-in.
 

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Discussion Starter · #6 ·
I didn't add an entire bottle into the converter as I couldn't seem to get all of it to fit, but I definitely put every bit of 3/4 or more of a quart in there. I reckon I'll just finish off that bottle plus 4 more for the break-in?
 

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Just some guy
67 coupe, 69 Sportsroof, 86 hatchback
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Even though torque converters hold three or more quarts when running some are hard to fill on the bench. GM T125/440 converters take like 15 minutes to take a half quart. Old C6 converters will swallow a whole quart about as fast as you can pour. Rule of thumb is at least 1/2 a quart and a full quart if possible. Sounds like you are good to go.
 
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