904/727 torque converter spline counts

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rumblefish360

rumblefish360

I have escaped the EVIL Empire State!
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What are the spline counts for the torque converters on these trannys?
Isn't there year differences?

Currently dealing with a 904. It is not in front of me.
 
through 66 727's used a 19 spline. 67 and newer non lockup 727's were 24 spline and lock up 727's are 23 spline

Older non lock up 904's were 18 spline and I believe it was in 68 they went to 27 spline. Lock up versions were 26 spline
 
Awesome, thanks.

Year of the trans is I.D'ed on the trans pan rail?
 
I'm not sure if the actual year is stamped there but you can tell by the part #. There'll be 2 sets of numbers there and the first set is the part number. A lot of the time it starts out with PK then several digits. Post that and I should be able to tell you what year it is
 
Thanks, it may be a little bit before I get the trans back, but when I do.....
 
fishy68 said:
through 66 727's used a 19 spline. 67 and newer non lockup 727's were 24 spline and lock up 727's are 23 spline

Older non lock up 904's were 18 spline and I believe it was in 68 they went to 27 spline. Lock up versions were 26 spline
Click to expand...

Is there an easy way to tell a 904 converter from a 727 by looking? Snout diameter, etc?
 
rumblefish360 said:
Thanks, it may be a little bit before I get the trans back, but when I do.....
Click to expand...

Ok

67Dart273 said:
Is there an easy way to tell a 904 converter from a 727 by looking? Snout diameter, etc?
Click to expand...

Yeah the snout is the easiest way to tell. There is a big difference between the diameters but unfortunately I don't have any (727 or 904) converters here to measure the diameter. If I remember though the 727 snout is right at 2" o.d. and the 904 is at least 1/4" smaller than that.
 
fishy68 said:
Ok



Yeah the snout is the easiest way to tell. There is a big difference between the diameters but unfortunately I don't have any (727 or 904) converters here to measure the diameter. If I remember though the 727 snout is right at 2" o.d. and the 904 is at least 1/4" smaller than that.
Click to expand...

Snout diameter is 1.490" on the 904 Converter & 1.870" 0n the 727 Converter.
 
That is great to know. I don't know why I didn't just "try" that. THANKS!!
 
OK, it has been awhile but here are the numbers;

Trans #1;
8410 063 7A 2959 ... 3520
08128633

Trans #2;
2801536Y
2517783
 
Trans # 2 is a 904 from a 67 Cuda/Dart/Valiant with a 273.

Trans # 1 is a lot tougher because all the trans numbers in my list start with either 2, 3 or 4 and are 7 digits in sequence so I'm not sure what to make of that one. If it's possible the 8 at the beginning is really a 3 and you ignore the space and one zero you have 3410637 which is a 1970 904 from behind a 318, but that's a real stretch of a guess. One thing I forgot to mention earlier that the first group of numbers are all that shows up on my list so you can ignore the second group of numbers
 
OK I'll check the numbers again. Thanks for the help.

My trans guy said the '67 was stupid clean inside. A real honest pleasure to work on. He was very surprised.
 
fishy68 said:
Ok



Yeah the snout is the easiest way to tell. There is a big difference between the diameters but unfortunately I don't have any (727 or 904) converters here to measure the diameter. If I remember though the 727 snout is right at 2" o.d. and the 904 is at least 1/4" smaller than that.
Click to expand...
The pilot on the late 904 and the 727 are both 1.810", the early 904 used a 1.55" pilot (up to late 66, I believe) Just been doing research for a swap - cheech14
 
cheech14 said:
The pilot on the late 904 and the 727 are both 1.810", the early 904 used a 1.55" pilot (up to late 66, I believe) Just been doing research for a swap - cheech14
Click to expand...
Yes that's true. If you'll re-read my post you'll note that I said the snout (the part that slips into the transmission) not the pilot (the part that slips into the crank). The snout was indeed a different size between 727 and 904 all through the run of both transmissions
 
fishy68 said:
Yes that's true. If you'll re-read my post you'll note that I said the snout (the part that slips into the transmission) not the pilot (the part that slips into the crank). The snout was indeed a different size between 727 and 904 all through the run of both transmissions
Click to expand...
My Bad! did not register in my little pea brain - the "snout" on a 727 is 1.872 - 1.875, on a 904, 1.495 - 1.498! Yes!!! Good way to tell! Cheech14
 
As a side note/ update

The trans is indeed a 18 spline count and finding a aftermarket converter was basically impossible though I may have missed a rock to turn over. I simply went down the block to have the OE unit modified.

These guys handled it for me and I’m happy with the results.
ProTorque High Performance Drag Racing Torque Converters

I have the “Pro Drive” with some of the “Bullet Race Drive” parts.
700+ HP not a problem.
 
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