340 and 904 trans

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ir3333

ir3333

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Who have used a stock 318 converter behind a 340 ?
What were your cam specs and what was the stall speed ?
 
Why would you use a 318/904 convertor behind your 340?
Are you using a 904 transmission or a 727? If you're using a 727 trans, the 904 convertor hub is a lot smaller than the hub on a 727 transmission.
 
Car came with a 340/904 and new stock 318 converter.
pulled engine and rebuilt trans to install in another project and am considering reusing
all.
...emphasis on new build will be braking/handling/cruising/mileage
 
...thinking of using a short duration cam with a bit more than stock lift to preserve compression for good lo rpm torque.
...318 converter would stall higher behind the 340 and just wondered if anyone has a stall figure for this combo..say 206/210 duration on the intake.
 
discharger1332 said:
it all depends on the cam in the 340, and gears. if it works why not run it?
Click to expand...
Sorry dont have the specs,I pulled the 727 out of a 68 340 cuda,all factory,had a 904 that had been rebuilt also had a new convertor for the 904,put it in made a few changes but it still works great.Other than it has more room and different shift points it works great.
 
The 904 used the same converter from 68-on (until the lockup unit) in both the leaning tower of power and the 318. The converter was a factory low stall, and from the factory had a low stall decal on it. To the best of my recollection this was the only converter available for the 318.
And there is nothing wrong with using a 904 behind a 340. Just make sure that you get the RIGHT converter for your application. For all practical purposes for the street/cruising no more than 2500 rpm is typically recommended, unless you've got a killer engine that needs a lot of stall.
I've attached a converter high stall specification sheet for you (hopefully). When I worked in the industry this was the form custumers filled out for us. It is an industry standard, as without the proper information it is almost impossible to get the right converter for you application.
If the spec sheet is not attached, send me an email with your email address and I'll send it to you.
 

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Mr transman....any idea what the stall speed would be on a factory 727 ,80's convertor from behind a 360, van application? It has a "Hi-Stall" sticker on it.

Thanks in advance!
 
Low stall probably 1400-1500 on a guess. When we rebuilt converters we never (as an industry) never really persued their stall speed as it wasn't necessary. You phoned in and asked for a converter for a specific transmission and engine combination and you got the converter required. High stalls were a different game, lots of questions to the customer that needed to be taken care of before any high stall even sold.
One thing that I'd like to mention, your chances of getting a NEW CONVERTER for anything other than a NEW car are two, slim and none, they don't make them for older cars, there's no reason to.
 
transman said:
Low stall probably 1400-1500 on a guess. When we rebuilt converters we never (as an industry) never really persued their stall speed as it wasn't necessary. You phoned in and asked for a converter for a specific transmission and engine combination and you got the converter required. High stalls were a different game, lots of questions to the customer that needed to be taken care of before any high stall even sold.
One thing that I'd like to mention, your chances of getting a NEW CONVERTER for anything other than a NEW car are two, slim and none, they don't make them for older cars, there's no reason to.
Click to expand...

Do you mean they're phasing out converter manufacturing for older 727's, 904's, T350's, etc, etc.??? Are the only ones you can buy from Summit, TCS, etc rebuilt ones?
 
Before the used 360 developed a knock, this was a 360, mild cam, out of a 77 van, unknown history. The 727 (still in the car with 318) power brakes to about 1700-1800. The 360 was a tad more but not much, same converter. (I knocked the weights off for the 318)
 
65Val said:
Do you mean they're phasing out converter manufacturing for older 727's, 904's, T350's, etc, etc.??? Are the only ones you can buy from Summit, TCS, etc rebuilt ones?
Click to expand...

Yup, new only from Car makers, and only for current production transmissions.
Not a $$$$ wise deal for them to make new units for 40 year old cars, or anything not current. I worked for a Chrysler dealer back in the day, and on the box a converter would be in would be "rebuilt for Chrysler", and when I worked for a GM dealer the converters came in a box with either the letter R in front or behind the part number. The R stood for rebuilt. Summit, Jegs, etc. buy from rebuilders, TCS rebuilds their own.
 
I have a stock 68 318 904 converter behind my mild build 360 and it is brake stalling at 2100 rpm. Mine didn't have anything marked low stall on it.
 
Hersbird said:
I have a stock 68 318 904 converter behind my mild build 360 and it is brake stalling at 2100 rpm. Mine didn't have anything marked low stall on it.
Click to expand...

If the converter was an original factory converter, it would have a low stall decal on it. I never seen an original factory converter of this type that didn't. Most aftermarket converters when rebuilt are painted and the decal is often comes off during the cleaning stage. Your 360 produces more torque than a 318 , and couple that with the fact you've given it a mild build would account for the higher stall than a stock 318.
 
I was hoping for 25-2600 as a factory "high stall" should have given, but as it stands, even with 2.76 gears my car is already traction limited. Once I get the 3.25s in should be awesome for a street car. My 360 is set up for good low rpm torque.
 
Hersbird said:
I was hoping for 25-2600 as a factory "high stall" should have given, but as it stands, even with 2.76 gears my car is already traction limited. Once I get the 3.25s in should be awesome for a street car. My 360 is set up for good low rpm torque.
Click to expand...

I had a couple of questions in the back of my mind in regard to the 904 transmission/318 engine that were bugging me, so I went over to the converter shop this morning and had a conversation with the shop foreman.
This is the information he gave me on these converters.
The 6 cylinder 904 converter from the factory is a high stall converter, that behind the 6 would give about 1300-1500 rpm stall range.
The 318 904 converter was a low stall unit in the 1400-1600 rpm stall range.
He said that because of a now low supply of 6 cylinder cores to be rebuilt, they mainly sell the 318 converter, as do most converter rebuilders ,for either engine. Nobody has ever complained about a difference in stall speed, as he suspected the average driver wouldn't notice the difference in a normal car. He wouldn't give a 100% guarantee on the stall speeds, as his old information sheet he had from Chrysler had long since disapeared and really was never an issue for them. When I asked about true factory high stall Chrysler converters, he said that only the Hemi and the 69-73 340 were factory high stalls, and as I recall, if I spoke to you on the phone and you needed one of these factory high stalls, they were core in first, as these cores were hard to come by and we never had any cores in stock. He also pointed out to me that if you use a 318 converter behind a 360 engine, you'll need to add weights to the converter to balance it properly as the 360 from the factory has a cast crank, while the 318 has a steel crank. I mentioned that I've seen weights you can purchase in the after market and weld them on yourself. He said while that is a novel idea, how do you know where the weights go, and how much weight is required to balance the converter correctly. His comparison was that adding weights yourself would be like trying to balance a tire yourself without a balancer of some type.
I'm going to do some digging on the factory rated stall speeds on these converters and if I find them, I'll post them here.
 
B+M makes a weighted flexplate....takes the guesswork out of using a 360 cast crank engine in front of a neutral-balance converter 904.
 
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