What rpm stall converter should use?

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rumblefish360 said:
In order to even make a guess, your missing over half of the important information needed to do so. How about some dang details?!?!

Start with the cam specs.

Your also better off with a 904.
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I’m in a bad place without knowing the camshaft specs or the cylinder head valve size? The engine was built by the person I bought the car from.
What makes 904 a better transmission than a 727?
 
Last edited:
rumblefish360 said:
In order to even make a guess, your missing over half of the important information needed to do so. How about some dang details?!?!

Start with the cam specs.

Your also better off with a 904.
Click to expand...
The reason I’m putting the 727 trans in, because I broke the 904.
 
RustyRatRod said:
It's just not like that anymore.....that is.....as long as you spend the money for a GOOD converter. If I had a stock stroke 360, 3500 would be my minimum flash for a hot street car. If I was thinking of throwing some strip in too, I would jump that to 3800-4200. There are some off the shelf converters that will work, but you need to talk to a good converter company and find out. They need to know it's going to be street driven so they'll know to make it tight enough so it will not slip and produce a lot of excess heat.
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That’s good thank you.
 
rumblefish360 said:
In order to even make a guess, your missing over half of the important information needed to do so. How about some dang details?!?!

Start with the cam specs.

Your also better off with a 904.
Click to expand...
The reason I’m putting the 727 trans in, because I broke the 904.
 
66fyssh said:
Fill out and submit the "spec sheet " on the PTC website. Depending on rear gears and tire diameter they'll probably recommend their 9.5".

Your build is somewhat similar to mine. 5.9 Magnum, mid-size cam, Edelbrock 2.02 heads and 650 AVS, 1.03 torsion bars and HD Espo springs. 3.55's and 26" tires. I have their 9.5" in a 904.
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What rpm does it flash at.
 
AJ/FormS said:
how much street versus how much strip?

On the Street;
3.91s are usually too much gear for the street (just spinning right thru First) but maybe not with the Caltracs .
3.91s @5500 will get you 44mph in First/73 in Second........ so 60 in Second will be 4500. You said "mild roller" so 4500 will be just climbing up the power-curve..........
There used to be a guy on FABO, name of Yellow Rose who many times extolled 4.56s for street. and the reason I think, is because it gets you about 60= 5400/5500 with those 28" tires. He was a smart man, and I miss him..
The A999 /1.54 Second gear) will get you there with 4.30s, and with a lockup TC will get you 65=3350rpm. Jus saying.

But at the track, in Third gear; 3.91s will get you about 106= 5500; just about right for highest trapspeed with a mild roller cam.

The question then remains;
how much street-driving, versus how much strip?
Your gears are saying strip, so then others have given their opinions, which seem good; ( I know nothing about racing)..
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PG Duster said:
What rpm does it flash at.
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Yours and his converter won't be the same flash point, even if they're the same converter. Differences in the vehicle combination will make the flash points different. PTC is a good company, Percision of New Hampton another. There's also Frank Lupo at Dynamic, Edge and Coan. Any of those can build you a quality converter. You need to remember to tell them though, that you want it tight enough for a street car.
 
AJ/FormS said:
how much street versus how much strip?

On the Street;
3.91s are usually too much gear for the street (just spinning right thru First) but maybe not with the Caltracs .
3.91s @5500 will get you 44mph in First/73 in Second........ so 60 in Second will be 4500. You said "mild roller" so 4500 will be just climbing up the power-curve..........
There used to be a guy on FABO, name of Yellow Rose who many times extolled 4.56s for street. and the reason I think, is because it gets you about 60= 5400/5500 with those 28" tires. He was a smart man, and I miss him..
The A999 /1.54 Second gear) will get you there with 4.30s, and with a lockup TC will get you 65=3350rpm. Jus saying.

But at the track, in Third gear; 3.91s will get you about 106= 5500; just about right for highest trapspeed with a mild roller cam.

The question then remains;
how much street-driving, versus how much strip?
Your gears are saying strip, so then others have given their opinions, which seem good; ( I know nothing about racing)..
Click to expand...
70% street and 30% strip
 
PG Duster said:
Will heat be a problem, I have a 11 3/4” by 9 1/2 trans cooler on the car. Mounted in front of the radiator.
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Not if you get the right converter. That means a “tight” in the stall you want. Not a drag race (or loose) converter.
 
PG Duster said:
How much would a torque converter like that cost? We used to have a good torque converter builder in California named “continental torque converters , but they went out of business.
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Probably around $600.00 now with everything going up in price. But we’ll worth it. Kim
 
PG Duster said:
Will heat be a problem, I have a 11 3/4” by 9 1/2 trans cooler on the car. Mounted in front of the radiator.
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Nope, not as long as you specify you want a tight converter. Even with a loose converter, you won't have a heat issue with a good cooler like you have. But you want a tight one for the street.
 
A somewhat easy to understand explanation of things: https://www.svtperformance.com/threads/torque-converter-stall-torque-ratio-str-guide.1113661/

After reading that, yikes, yeah, I’d just call one of the companies others here have mentioned (including Turbo Action and FTI) and get the right converter the first time. There are a couple you could run “out of the catalog” and be happy with, but for the amount of money you’ve paying regardless it’s best to let the pros spec “the ideal one”
 
I have several modern 727 converters 3000/3500/4200/5000
You remember how I hoard stuff = That has not changed since to 70's
 
Factory 340 cars came with 3500 stall. The would brake stall a 2800-3200 depending on the torque of the motor. Same converter in a Big block car will stall at 3000-3500. I can remember installing a 727 out of a truck with 2200-2400 low stall converter. Turned the car into a real pig
 
With the broken 904 in this car that I bought it has a 6 cylinder torque converter in it. I will be removing that one when I put the 727 trans .Why would someone put that 6 cylinder converter behind a magnum 360?
 
PG Duster said:
With the broken 904 in this car that I bought it has a 6 cylinder torque converter in it. I will be removing that one when I put the 727 trans .Why would someone put that 6 cylinder converter behind a magnum 360?
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Stupid is my guess.
 
Oldmanmopar said:
Factory 340 cars came with 3500 stall. The would brake stall a 2800-3200 depending on the torque of the motor. Same converter in a Big block car will stall at 3000-3500. I can remember installing a 727 out of a truck with 2200-2400 low stall converter. Turned the car into a real pig
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In 1977 I bought a factory stock 1971 340 Duster with 8 3/4 sure grip rear end 3:91 gears and a 727 trans, it did not foot brake stall that high. Maybe The 1970 340 would stall like that.
 
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