• When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

Please help.....

B

biggerthanyou

New Member
Local time
8:59 PM
Joined
Mar 4, 2020
Messages
3
Reaction score
1
Location
Maine
Hey all. I been researching my problem for 2 months and I'm getting nowhere. Conflicting reports on every post. Just need a straight answer from a person that has completed my nightmare. Here goes.
1 I have a 65 Plymouth belvedere with a 273 904.
2 I have a brand new 1984 360 LA I want to install.
3 I finally found the motor mounts that needed to be changed
4 finally figured out the oil pan I needed with pick up
5 have the wieghted fluid damper
6 have the B&M 904 flexplate
7 running headers
8 ok my last issue. Can I run the converter already in the car? I'm hearing no and yes. I'm hearing with the B&M flexplate I can. Then I'm hearing I need a 360 converter. Please please only respond if you have done this. I'm thousands in the negative on this so called easy swap I'm trying not to waist any money on maybes.. thanks for whoever can save me from this nightmare.
 
Last edited:
With the "proper" B&M flexplate you can.Did a 66 Charger with a 74 360 and 74 904. B&M makes 2 for the small block. The one you need for external balance will have a large notch in it. Summit Racing B&M # 10239
 
Last edited:
I don't know about the B&M flexplate. But we did swap a 360 into a 65 Barracuda many years ago, and used the original flexplate from the 273.. WRONG! Vibrations all the time.. Ended up rebuilding the 273, and stuck it back into the car. No more issues. And I dropped the 360 into my old 78 Dodge pickup, and put probably 200K miles on it before selling it. So, the 273 flexplate don't work with a 360 UNLESS this B&M plate mentioned is balanced for such a swap. Good luck, sounds like you have the other stuff needed.
 
I recall the Mopar racing "bible" has specs to add a weight on the neutral balance converters.
Mike
 
I don't want to add to the confusion, but I went through a lot of research to get the correct combination for my 360 with a 727.

Have a look at the information below...it may help out somewhat.

B&M Flexplate part numbers.....
upload_2020-4-27_10-43-4.png


I used a weighted B&M
upload_2020-4-27_10-45-24.png


with a PowerForce Harmonic Dampener
upload_2020-4-27_10-49-1.png


upload_2020-4-27_10-48-24.png


upload_2020-4-27_10-46-25.png


There is a lot of information out there, but you have to be careful with the combinations.

upload_2020-4-27_10-50-20.png
 
If you use the right flexplate, do you still have to add weight to the converter? I thought that right weighted flex plate eliminated the need for weight on the converter.
 
tonysrt said:
If you use the right flexplate, do you still have to add weight to the converter? I thought that right weighted flex plate eliminated the need for weight on the converter.
Click to expand...
Using the combination I have - weighted flexplate & dampener, you must use a 'neutral-balanced' converter....something I went to great expense here to achieve. The first shop were absolute morons as it turned out. I ended up chasing down an expert in the field.
 
If the 360 B&M Flexplate has holes that fit you 904 converter and clears the starter nose you are good to go. The cut out takes the place of the 360 weights. The cut out is 180 degrees different from the factory 360 balance weights. Thus it's balanced without any extra converter weight. Engine balance isn't affected by the type of neutral balance converter.
Doug
 
That B&M flexplate has bolt pattern for 10 and 11” converters.
 
These guys are right. If you have the correct B&M flex plate, the converter needs to be neutral balance (no weights).
 
Does anyone know about the converter snout going into the crankshaft? I'm also hearing that's an issue? Jesus, why the hell is this such a pain? Sorry for venting. I really appreciate all your help everyone. I'm just going crazy over hear lol
 
biggerthanyou said:
have the B&M 904 flexplate
8 ok my last issue. Can I run the converter already in the car? I'm hearing no and yes. I'm hearing with the B&M flexplate I can. Then I'm hearing I need a 360 converter. Please please only respond if you have done this.
Click to expand...

As others stated above, it is an either/or for the converter. Either you need a weighted converter for the 360 or you need a "weighted" or non neutral flexplate, as pictured above in post #5.

Also, I'll add this, just to help out. Don't stress about any of this. This is a hobby, no one needs it to live. The garage should be a happy place, where you can relax, like a Caribbean beach full of cheeseburgers served by supermodels. Cars are glass, rubber and steel, and will never know when you're pissed at them.
 
Last edited:
The B&M flexplate takes care of the balance issue, the pilot hub diameter is tough to say, some tech books say it changed in 64 so 65 should be good.. Other tech info shows the change in 67... I know on 727's & 904's the input shaft changed in 67 but I want to say the crankshaft/convertor pilot change was 64.... Worse case you have a spacer machined... The early T/C pilot is 1.55" the late pilot is 1.81" so you could easily use a spacer...

Only way to know for sure is to take it apart....

The other way is to use a 360/904 convertor but since the input shaft changed in 67 you would need to change that too... Do it the easy way, use the B&M flexplate & if there's a time factor just have the 1.55" I/D 1.81" O/D spacer available when you tear it down...
 
Last edited:
Could you please show me where this spacer would go? Or maybe explain?
1 Wild R/T said:
The B&M flexplate takes care of the balance issue, the pilot hub diameter is tough to say, some tech books say it changed in 64 so 65 should be good.. Other tech info shows the change in 67... I know on 727's & 904's the input shaft changed in 67 but I want to say the crankshaft/convertor pilot change was 64.... Worse case you have a spacer machined... The early T/C pilot is 1.55" the late pilot is 1.81" so you could easily use a spacer...

Only way to know for sure is to take it apart....

The other way is to use a 360/904 convertor but since the input shaft changed in 67 you would need to change that too... Do it the easy way, use the B&M flexplate & if there's a time factor just have the 1.55" I/D 1.81" O/D spacer available when you tear it down...
Click to expand...
 
It is actually a bushing that goes over the torque converter "snout" or better known as the crankshaft register.Thus taking up the space between the crank and the smaller snout of the early 904 converter to the larger diameter 360 crank.
This is shown in post #15
 
You must log in or register to reply here.

Similar threads

Charger72
904 Transmission Control/Shift Lever What do I need?
Replies
5
Views
456
Charger72
Charger72
1968rt
Identifying a reverse rotation crankshaft - with pictures
Replies
0
Views
529
1968rt
1968rt
1966Belvert
904 torque converter - What do I need?
Replies
3
Views
842
Dave6T4
Dave6T4
Charger72
Mating a 904 transmission to a 360
Replies
7
Views
2K
Cranky
Cranky
D
Converter ID help
Replies
1
Views
291
4mulas
4mulas
Auto Transport Service
Back
Top