mystery 904 stall converter

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dgswinger

dgswinger

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well i have this 904 9" stall converter it came with a race built 904 trans i got. the guy didnt know how much stall it was... here is the story i got when i picked up the trans. this came from 11 sec. barracuda that had a 318 in it i know sounds a little far fetched but i did see the engine also. it was a 318 with forged piston .030 over. had a solid roller cam in it. and massively ported x-heads on it.... im assuming this was an all high RPM build so i would assume this converter is prob a 4000 or higher. look at the pics and here are some of the stampings on it.

im guessing the Motts name stamped on it is either the brand/builder or the persons name it was custom built for.
numbers are
11708-904
T-6
P093S
11102996

any info or opinions would be great!!

only issues i have seen with it is the hub had some flash rust on it that i took scotch-brite and removed then greased. and the paint is flaking off the wheel side of it. I was told it worked great but i never rode in the car. the guy was removing the race parts to restore the barracuda.

if you would like to own this converter make me an offer i know this isnt the classifieds i would list it there but i dont like to sell things i dont know anything about but if you want to take a chance on it make me an offer. probably too much converter for anything i will ever build.
i would also trade for a 2800 stall for a 727

thanks for any help!!
 

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dgswinger said:
well i have this 904 9" stall converter it came with a race built 904 trans i got. the guy didnt know how much stall it was... here is the story i got when i picked up the trans. this came from 11 sec. barracuda that had a 318 in it i know sounds a little far fetched but i did see the engine also. it was a 318 with forged piston .030 over. had a solid roller cam in it. and massively ported x-heads on it.... im assuming this was an all high RPM build so i would assume this converter is prob a 4000 or higher. look at the pics and here are some of the stampings on it.

im guessing the Motts name stamped on it is either the brand/builder or the persons name it was custom built for.
numbers are
11708-904
T-6
P093S
11102996

any info or opinions would be great!!

only issues i have seen with it is the hub had some flash rust on it that i took scotch-brite and removed then greased. and the paint is flaking off the wheel side of it. I was told it worked great but i never rode in the car. the guy was removing the race parts to restore the barracuda.

if you would like to own this converter make me an offer i know this isnt the classifieds i would list it there but i dont like to sell things i dont know anything about but if you want to take a chance on it make me an offer. probably too much converter for anything i will ever build.
i would also trade for a 2800 stall for a 727

thanks for any help!!
Click to expand...
 
Hello,
I just bought basically the same converter as you in a recent purchase. Same deal to, race duster with a 904, 9 inch Motts with very close numbers. Did you ever figure out what it is? I haven't had any luck yet.
 
ChuckDock said:
Hello,
I just bought basically the same converter as you in a recent purchase. Same deal to, race duster with a 904, 9 inch Motts with very close numbers. Did you ever figure out what it is? I haven't had any luck yet.
Click to expand...
I wish I had more information but I still dont know anymore than I did.
 
Race converters are built for a specific application. Stall speeds can and will vary depending on what was done internally to the converter. Stall speeds on a 9" converter range from around 3700 to 4500, again depending on internal modifications. The number 11708-904 may be the serial number of the converter.
Unfortunately, unless the converter is cut open and inspected by a knowledgeable high stall converter builder, or you can contact the original builder of the converter it is really hard to say what stall a converter is.
 
transman said:
Race converters are built for a specific application. Stall speeds can and will vary depending on what was done internally to the converter. Stall speeds on a 9" converter range from around 3700 to 4500, again depending on internal modifications. The number 11708-904 may be the serial number of the converter.
Unfortunately, unless the converter is cut open and inspected by a knowledgeable high stall converter builder, or you can contact the original builder of the converter it is really hard to say what stall a converter is.
Click to expand...
That's the million dollar question, who built the converter. MOTTS that's printed on the converter doesn't seem like a real company.
I'm more just trying to figure out the spec's on it more out of curiosity but definitely don't want to cut it open. I picked mine up with a wicked 340 and a 904 all done up as well, but the guy who sold me the setup said the converter was a Coan converter, but after looking at their website, that doesn't seem so.
This winter I'll drop the 340, trans and new rear end into my 67 cuda. It will probably kill the street-ability out of the car from my numbers matching 273 setup, but at least I'll be able to do crazy burnouts, lol.
 
Keep in mind that the 904 converter has two different sizes of pilot (the part that sits into the crank) The early (L1962 to 1967) had a pilot size of 1.550 inches. There were also some (unsure of the application as my catalog doesn't give me this information) 1968-1972 that also had this small pilot. From 1968 - on with the 225-318-360" engines all had the large pilot size of 1.810". Your 273 might have the small diameter hole in the crank, while the 340 will have the larger crank hole. Something to watch for.
To the best of my knowledge, ALL 340's came from the factory with the 727, not the 904. The 71 Duster I bought new had the 727 in it, as did any other automatic equipped 340 I've looked at.
Hope this helps.
 
transman said:
Keep in mind that the 904 converter has two different sizes of pilot (the part that sits into the crank) The early (L1962 to 1967) had a pilot size of 1.550 inches. There were also some (unsure of the application as my catalog doesn't give me this information) 1968-1972 that also had this small pilot. From 1968 - on with the 225-318-360" engines all had the large pilot size of 1.810". Your 273 might have the small diameter hole in the crank, while the 340 will have the larger crank hole. Something to watch for.
To the best of my knowledge, ALL 340's came from the factory with the 727, not the 904. The 71 Duster I bought new had the 727 in it, as did any other automatic equipped 340 I've looked at.
Hope this helps.
Click to expand...
Fortunately for me, this 904 and converter was bolted to the 340 when I bought it so someone must have figured out what they needed. I was told they went with the 904 just because its lighter. It has the reverse manual valve body and a deeper oil pan as well. I couldn't use the 273 with this trans/converter setup either way. It makes no horse power, though runs really well. I had a 71 340 duster, it was a great car. it has a stick though.
 
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