Recommend me a converter for this 273 - 727 combo

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trebor75

trebor75

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Plymouth Duster 70 - 273 - 727 - 8 3/4
273 (1965) Edelbrock intake & Edelbrock 4 bbl carb, 340 cam, headers, dual 2.5” exhaust
727 automatic
8 3/4 - 3.31 and sure grip
245/60 14 tires

It runs great as it is, but from a stop it would be nice to be able to launch just a little faster.
The little engine wakes up as soon as it picks up rpm and speed.

A friend suggested to try a different converter with a higher stall speed. I cant spend to much money, because when I can afford it a 360 will go into this car and I’m in Sweden and everything is really expensive I’m sorry to say.

So, any suggestions appreciated and if you could, let me kow if I need anything else besides the new converter to make the swap (different flex plate ect).

I have looked at Hughes Performance Street master converters and B&M Tork Master with different stalls from 2000 to 2500 rpm depending on model.
 
Do you have the small journal crank or the bigger (standard) size hole on the crank.
 
1970Duster said:
Do you have the small journal crank or the bigger (standard) size hole on the crank.
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I have to look this up and return. I bought the 273 and trans from a friend and dropped it right into the Duster. Either way, what do I need to consider?
 
I ask because the 360 and 273 (with original crank) have 2 different journal sizes. This means you'll end having to buy two different converters because of the size difference.
 
with what you have going for a combo....I would suggest something like a TCI sizzler stall converter (thats what I am running).

I think its advertised around a 2200-2500 stall

and the price was pretty good on it ( I think i paid around $300.00 for mine).
 
DusterDude72 said:
with what you have going for a combo....I would suggest something like a TCI sizzler stall converter (thats what I am running).

I think its advertised around a 2200-2500 stall

and the price was pretty good on it ( I think i paid around $300.00 for mine).
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I was thinking the same thing around 2200, but I know it can be a hard time trying to get converters for the small journal.
 
1970Duster said:
I ask because the 360 and 273 (with original crank) have 2 different journal sizes. This means you'll end having to buy two different converters because of the size difference.
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I see, thanks for pointing that out. I'm guessing that my 273 has the stock crank, but I will look it up to be sure. The 273 will stay in this car for at least 1-2 years, so I will still consider getting another converter for now, if I can benefit from it that is.
 
1970Duster said:
I was thinking the same thing around 2200, but I know it can be a hard time trying to get converters for the small journal.
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Can you explain this further, I dont quite understand. If we leave out that I will get a 360 in the future and then assume I have the stock crank on my 273 right now. Could I go with a converter that is advetrtised to fit my 727 trans?
 
68 273's have the large torque converter register so if it's a 68 engine (providing it's the stock crank) your in luck that it'll work with a 360. Also keep this in mind. You need to know what year your transmission is because 66 on back has a 19 spline input shaft and a 67 up has a 24 spline input shaft. Since you don't really know what you have you really need to take the trans. out and check the register size and input spline count before you order something, IMO.

BTW: the small register is 1.55" and the large register is 1.81"
 
fishy68 said:
68 273's have the large torque converter register so if it's a 68 engine (providing it's the stock crank) your in luck that it'll work with a 360. Also keep this in mind. You need to know what year your transmission is because 66 on back has a 19 spline input shaft and a 67 up has a 24 spline input shaft. Since you don't really know what you have you really need to take the trans. out and check the register size and input spline count before you order something, IMO.

BTW: the small register is 1.55" and the large register is 1.81"
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The enginge is from 1965, so it very well could be the small register. But you are right, I need to take the trans out to be sure.

I had no problems finding converters for the 24 spline converter, but does anybody know where to get a converter with the small snout and 19 spline, if it turns out to be what I need? I did not see any of those in my search.
 
trebor75 said:
The enginge is from 1965, so it very well could be the small register. But you are right, I need to take the trans out to be sure.

I had no problems finding converters for the 24 spline converter, but does anybody know where to get a converter with the small snout and 19 spline, if it turns out to be what I need? I did not see any of those in my search.
Click to expand...

Recently a fellow mentioned Hughes is making him a torque converter with the old size specs. for the same price as a new style converter. I have used Hughes converters and they seem to be good converters and are reasonably priced but the only thing is they always (in my experience) seem to be a little tight on the stall speed spec. In other words if you order a 2500 stall it may only stall 2200-2300 rpm. With that in mind you may want to order a slightly higher stall than wanted.
 
Thanks for your valuable info! Now I know what to look for and where.

"Ifitsgotwheels", since you also have the 273, may I ask how much difference did the higher stall converter make for you?
 
I would think with the 273, you would want something in the 2800 to 3000 range, Since the engine doesnt make alot of torque. There are alot of shops that can build your current converter, but it would probably ill you in shipping both ways.
 
Update

I looked up the numbers on my 727 trans and its: PK3681862 245065583
I found info through this page: http://www.mymopar.com/downloads/transguide.pdf

It is infact from 74-75 727 and Hvy Duty, whatever that means?

So I know alteast that it is a 24 spline input shaft and that leads me to belive that the engine have the large torque converter register. Or have you ever heard of a combo of a 74-75 727 bolt up to a 1965 273 with the smaller register?
 
Give Dynamic converters a call http://dynamicconverters.com/ tell them every ounce of info on your car and let them build a custom converter for you. It will drive normal on the street but when you hit she will flash. Not a off the shelf converter another words. They more than likely will quote you a higher stall so be prepared but they know what they are doing. Like higher on the price also but gas mileage, and the fun factor will pay off in the long run. There is another custom converter company that is always mentioned on here but I cant remember their name. That's what I would do anyways.
 
I'm going to suggest a 904 trans swap. The 727 just doesn't get the horses to the pavement like the 904 does.
Difference may be in the gear ratio. i really dont know.
I think a stall converter with that 727 still wont make you happy.
 
fishy68 said:
Recently a fellow mentioned Hughes is making him a torque converter with the old size specs. for the same price as a new style converter. I have used Hughes converters and they seem to be good converters and are reasonably priced but the only thing is they always (in my experience) seem to be a little tight on the stall speed spec. In other words if you order a 2500 stall it may only stall 2200-2300 rpm. With that in mind you may want to order a slightly higher stall than wanted.
Click to expand...

Fishy you are right on the money. I bought a used TCI Street Fighter converter and TCI advertises it to stall at 3500. I called TCI and they said that the converter will stall at 3500....but that it would only stall that high behind a very strong 360. When I described my mild 360 build to them the tech said that in reality I would only be looking at about 2800 stall. I have had several aftermarket converters through the years and I have yet had one flash to the maximum advertised speed, they were always short of the advertised stall speed .
 
RedFish said:
I'm going to suggest a 904 trans swap. The 727 just doesn't get the horses to the pavement like the 904 does.
Difference may be in the gear ratio. i really dont know.
I think a stall converter with that 727 still wont make you happy.
Click to expand...

Redfish, I'm with you on this. I can't see any real advantage with a 273 street engine needing a 727.
 
trebor75 said:
Update

I looked up the numbers on my 727 trans and its: PK3681862 245065583
I found info through this page: http://www.mymopar.com/downloads/transguide.pdf

It is infact from 74-75 727 and Hvy Duty, whatever that means?

It means just that. It's a 74 or 75 heavy duty trans.
Click to expand...

So I know alteast that it is a 24 spline input shaft and that leads me to belive that the engine have the large torque converter register. Or have you ever heard of a combo of a 74-75 727 bolt up to a 1965 273 with the smaller register?
Click to expand...

Only way it could bolt up is if the converter is custom made or the crankshaft in the engine is newer and has the big register.

I also agree a 904 would be much better for your low torque engine. You might still need some more stall speed but at least you don't have the power robbing effect of the 727 adding to the equation.
 
Thanks again all! The 727 Will have to stay though. Im saving up for a 340 or 360 in the future. But i think i Will go with a 3000 or 2800 stalling converter for the 273 meanwhile then.
 
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