What rpm stall converter should use?

-
PG Duster

PG Duster

Well-Known Member
Joined
Oct 23, 2021
Messages
326
Reaction score
266
Location
California
I have a 1974 Plymouth duster with a 360 magnum mild hydraulic roller cam, port job on steel cylinder head, Edelbrock airgap RPM intake manifold, 750 Holley carburetor vacuum secondary, Headers and a 2 1/2 inch exhaust with Flowmaster mufflers, CAL track traction bars and springs, Mickey Thompson drag radials 275 60/15. I’m going to use the car for street strip what stall torque converter should I use? I will be replacing the 904 transmission this week with a 727, it also has a 3:91 gear ratio with a 8 3/4 sure grip rear end. Thank you for your thoughts.
 
Last edited:
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.
 
Although he does say it's a mild hydraulic roller. 4200 might be a little high? Agree with above, need the cam specs and other info...
 
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.
 
Cam specs
Car weight (Actual, not what the paper work says.)
Compression ratio
Dyno’d the engine?
Estimated power
 
PG Duster said:
Wow, converters have changed over the years. That stall would be good for a mild engine for street/strip.
Click to expand...
Yes it has, tremendously. You can get a converter that'll flash to 5K in your combo, but be tight enough to drive everyday. It's the one BIGGEST mistake people make when making a choice. People think the converter will slip all the time like the old days and that's just not true anymore. As much as it's preached on here and people STILL want to put crappy 2500 stall converters in things. That'where the factory converters stalled.
 
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.
Click to expand...
You still likin it?
 
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...
I bought the car in February of this year, the engine was already rebuilt, the person said it’s a mild cam, which I can hear, and after market steel cylinder heads. The person was supposed to send me the specs, But you know how that goes I don’t know what the numbers are, he never sent them.
 
RustyRatRod said:
Yes it has, tremendously. You can get a converter that'll flash to 5K in your combo, but be tight enough to drive everyday. It's the one BIGGEST mistake people make when making a choice. People think the converter will slip all the time like the old days and that's just not true anymore. As much as it's preached on here and people STILL want to put crappy 2500 stall converters in things. That'where the factory converters stalled.
Click to expand...
That’s what I Remember , In the later 70’s I had a 3000 stall converter in a 1971 340 Duster and there was a lot of slip on normal driving.
 
PG Duster said:
That’s what I Remember , In the later 70’s I had a 3000 stall converter in a 1971 340 Duster and there was a lot of slip on normal driving.
Click to expand...
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.
 
PG Duster said:
So I can run a converter that flashes 3500 rpm on the street.
Click to expand...
Yes, you can run one that flashes to 5000 on the street. I know that's not what you need, but that's how much technology has changed.
 
I’m in a bad place without knowing the camshaft specs or the cylinder head valve size?
 
Love it!! It works amazingly well just driving around but when you want some fun...hammer it and you better be pointing in the right direction, lol.

I just bought a Sur-Grip from Roy so I'll be putting that in before too long.
 
oldkimmer said:
3500 from PTC, Ultimate, Dynamic etc. Converters are 1 of the most important parts of the puzzle. Kim
Click to expand...
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.
 
Last edited:
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)..
 
66fyssh said:
Love it!! It works amazingly well just driving around but when you want some fun...hammer it and you better be pointing in the right direction, lol.

I just bought a Sur-Grip from Roy so I'll be putting that in before too long.
Click to expand...
Oh my Lord. That thing's fixin to be dangerous. lol
 
The reason I’m putting the 727 trans in, because I broke the 904. That is a lot of good information, because I was going to put a 2800 stall converter in the 727 trans next week.
 
You must log in or register to reply here.
-

Back
Top