I have rebuilt my engine with a stout cam and other components. The cam specs ask for a 2200+ stall convertor. I ahve been driving it with the stock convertor till I have the cash for the new convertor. I tend to research too much but it does save me at times. I need to be sure I get the right torque convertor that will fit my trans. My car is a 66 Sport Fury 383 727 originally. When I got it, it had a 73 400 in it and I have since replaced it with a 383. I need to know how to identify the trans to be sure I get the correct torque convertor. I have replaced the tranny fluid and the filter and gasket I asked for was for a 727 and it was correct but are there different convertors for different years or do they all fit outside of stall speed?
Joined: Mon Oct 10 2005, 12:14PM
Location: Rochester IN
Posts: 152
I think all 727's are the same. I got Hughes 2400 stall (pt# HUP-24-25 from Summit). I was told it will flash around 3000 for a big block. I have had 3 tranys (1969, 73 & 78) in my fury, on two motors (383 & 440). they have all worked together.
Good Luck
<span class='smallblacktext'>[ Edited Tue Oct 24 2006, 10:48AM ]</span>
Joined: Wed Dec 21 2005, 07:34AM
Location: indiana
Posts: 791
I think '66 and older has a different spline count on the input shaft. I don't know how one can ID that from the outside, though.
If there was a 73 400 installed to this trans, though, I would think that the converter would have been balanced to the cast-crank engine, which would then become unbalanced with a typical steel-crank 383. Unless somebody did some different balancing or something on the 400...
There were some steel crank 400's, but not many. Those would have been the only internal-balance 400's. I think B&M makes a flex plate that is balanced so that a neutral balance converter can be used.
I also agree that some t-flites had different spline counts on the early transmissions. The question is, what years had what splines? I know there's a reference for this out there, I just can't seem to find it.
Chrysler converters typically have the flywheel ring gear welded on, and are attached to the crank by a small flex plate. Up until the Magnum engines, the balance weights (if needed) were also welded to the converter itself. This is different than (I think) all the other makes out there. So, there are a couple potential situations here. 1) IF the ORIGINAL 383 converter is still in the car, it is neutral-balanced, as all early 383's were neutral-balance steel crank engines. if your NEW 383 is ALSO a steel crank engine, everything will be perfect. 2) IF the PO replaced the whole engine/trans combo with a 400/727 replacing the 383/727, you'll PROBABLY have to come up with a neutral-balance converter for your 383. The FEW steel-crank 400's came in early manual-trans applications. 3) IF the PO was a lazy SOB and just threw the 400 in on top of the old 383's trans and converter, then it almost certainly vibrated a good bit. Putting your NEW 383 (ASSuming steel crank again) on this combo will be fine. Conversely, if the PO put the 400 with it's MATCHING converter in to the 727, you'll have to swap the converter if your NEW 383 is steel crank.
The only way to check is to verify what balancer is on the front of the 400, and pull the inspection cover on the trans to see if there are weights welded to the converter. They're usually next to the drain plug on the converter, and there will be at least two of them, about 1"x1.5"x0.25" in size.
Nutshell version: There were cast crank 383's AND 400's, and BOTH used the SAME balance weights (so did cast crank 440's for that matter). There were steel crank 383's AND 400's, and BOTH were neutral-balance (so were MOST 440's).
You need to do a little more research on what you have on hand before you can (should) spend money.
You state that you have been driving it with the stock converter and I assume all is ok.
Pull the converter and check it for any weights- I doubt you will find any. Count the number of splines on the shaft. Order your new converter.
When high performance balancing is done I would include a neutral balance flexplate as part of the combination. However, it sounds like it is a little late for that with your project- No worries.
Flexplate- if you use the same flexplate you have now, then bolt it up and drive.
if you plan on changing the flexplate, check what you have... does it have a scallop cut out of it? if so, put the same style back in. Does it have weights or balance holes in it- probably not, but if so... get the same style and have it balanced to match.