Factory torque converter

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JacksonTaylor

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I have the 454/TH400 and am looking into a new TC. Can anybody tell me what the factory diameter and stall was? TIA
 

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The factory converter was a 13 inch, probably around 1800 to maybe 2000. If the engine is stock, then a stock converter would work well. If you have done any engine modifications, most likely a higher stall speed is needed. Call Coan, ATI, Hughes, any of the aftermarket converter builders. Have as much info as possible about the engine and driveline build. The more info you have, the better the converter build. A custom converter won’t cost much more than a off the shelf part, but will be perfect for your application.
 

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I went to D&P Converter out of Sacramento, CA. They’re regarded as one of the better builders in the country by most of the tranny shops I’ve talked to. They build stuff from stock, to race cars, dragsters and ultra four rigs. Only $130 for a nice converter. I paid $310 from Hughes Performance. So Matt is definitely correct—it’s cheaper to have one built than one of the off the shelf “high end” units.
 

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Thanks so much for the replies. I ordered a B&M street/strip TH400 and got the (approximately) 11" 2700-3000 converter from Jegs.
 

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Thanks so much for the replies. I ordered a B&M street/strip TH400 and got the (approximately) 11" 2700-3000 converter from Jegs.
Obviously not a work truck...?
 

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shiftpro

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The B&M converters I've dealt with have had a much lower than advertised stall speed.
I think... that your cam/engine characteristics will effect stall speed. For example, a big cam that doesn't produce much power say below, 2800 rpm, will not get a stock convertor to grab at 1800.
If a high stall convertor advertised at say, 2800 stall speed, only has a stock engine/cam in front of it it will stall sooner than the advertised stall speed.

Again, this is only my theory, half assed guess. Something I've noticed and wondered about for years. I could be full of ****.
 

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Stall speed is directly related to load and engine power. For example, let’s say you have a mild big block making 425 lbs ft of torque. The rear axle ratio is 3,08 with 35 inch tires. And the B&M converter has a max stall speed of 2800 rpm. Take off the 35 inch tires, install 28 inch, the engine load is now lower, that drips the stall speed to 2600. Put the 35 back on, swap the mild big block for a torque monster 540, now the stall speed might be 3000. Get rid of the 3.08 gears, bolt in some 4.10s, now the stall speed is back to 2600. These are all just speculation, there is a bunch of science in converters. That’s why I suggested a custom converter, who knows exactly what a off the shelf converter will do.
 

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I understand there's variables and there's a science behind it, but the B&M converters I've had experience with stalled (or "flashed"... is there really a difference?) a couple hundred rpm below the lowest advertised stall speed, even behind engines that made more grunt than stock. I remember a couple in particular that felt just like a stock converter.
 

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Stall speed is directly related to load and engine power. For example, let’s say you have a mild big block making 425 lbs ft of torque. The rear axle ratio is 3,08 with 35 inch tires. And the B&M converter has a max stall speed of 2800 rpm. Take off the 35 inch tires, install 28 inch, the engine load is now lower, that drips the stall speed to 2600. Put the 35 back on, swap the mild big block for a torque monster 540, now the stall speed might be 3000. Get rid of the 3.08 gears, bolt in some 4.10s, now the stall speed is back to 2600. These are all just speculation, there is a bunch of science in converters. That’s why I suggested a custom converter, who knows exactly what a off the shelf converter will do.


Ok... let's go with the 540!
 

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Obviously not a work truck...?
No, but the motor is still unmodified...I just want to get the right trans behind the motor before I make any new power happen.
 

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I don't understand much about converters. Not that it's very relevant here but on a Buick Grand National years ago I upgraded to a PT-51 turbo and was told by everyone that a stock 12" re-stalled at 2200 rpm would be adequate. Heck, I couldn't build even 2 lbs of boost on the line. Then someone asked me, "what's the elevation where you live?" I told him about 6800 feet. He yelled "why didn't you say so?!" I had no idea that elevation affects this. Ultimately, I got a 10" stalled to 3500 rpm and, when brake-boosting the SOB would build 10 psi instantly and turn the car sideways. Torque converters are definitely a bang-for-the-buck item.
 

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I don't understand much about converters. Not that it's very relevant here but on a Buick Grand National years ago I upgraded to a PT-51 turbo and was told by everyone that a stock 12" re-stalled at 2200 rpm would be adequate. Heck, I couldn't build even 2 lbs of boost on the line. Then someone asked me, "what's the elevation where you live?" I told him about 6800 feet. He yelled "why didn't you say so?!" I had no idea that elevation affects this. Ultimately, I got a 10" stalled to 3500 rpm and, when brake-boosting the SOB would build 10 psi instantly and turn the car sideways. Torque converters are definitely a bang-for-the-buck item.
Considering the technology involved, they are almost free...
 

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