904 to 727 swap

[Grindhouseproject]

Well the day I was dreading happened with my daily driver 72 fury wagon. Stoped at a light and went to pull away the little 904 slipped in every gear. It doesn’t do it all the time but it’s definitely time to fix it. Now I have a small block 727 sitting in the garage. I pulled it out of a 82 d350. It looks to have been gone through recently. Has a new converter to. I know it would be way easier to go through the 904 but I want to tow with the wagon and also been thinking about getting a big block for it one day. So here I am wanting to make a thread on how to do this swap.

I know with the 727 being about 4 inches longer I’m gonna need to shorten the drive shaft. Everything else looks like it should just mount up there. Only concern is the z bar for the column shift that looks to be different and I don’t fully know if any 727 column shift linkage will work or if I can modify the 904 one

 

[413]

Slip yoke slide into trans is different size
Make sure you have the correct flexplate.
Use the 727 dipstick and tube
yes shift linkage can be different, depends on what you have


Not a slam dunk swap, but doable.

 

[Grindhouseproject]

Slip yoke slide into trans is different size
Make sure you have the correct flexplate.
Use the 727 dipstick and tube
yes shift linkage can be different, depends on what you have


Not a slam dunk swap, but doable.

Still mad at myself I did not grab the slip yoke from the truck. I also grab the 360 from that truck so I have the correct flexplate. My main concern really is the linkage so I’ll craw under there tonight and take some photos. Here’s the 727 gonna also take the pan off tonight and take a peak inside.

 

[413]

What engine is in the wagon? You will need to address the balance weights on the converter also.

 

[Snotty]

Does that 727 have a lockup torque converter?

I wouldn't do it; I would fix your existing transmission. In addition to all the changes, you said you want to put a big block in in the future. If you do, you will need to swap transmissions again. Why do all that work twice?

 

[traintech55]

I did this swap before. You need the correct flex plate and torque converter, IE, 318 TO 727. linkage should be ok. You will need to have the driveshaft shortened.

 

[CBODY67]

Only "light-duty emissions" vehicles got lock-up converters, plus any HO engine cars. So the D350 trans should not be a lock-up converter.

Main issue to me is that if and when you do the RB engine swap, you'll need (as mentioned) a B/RB 727 to bolt to it, as the bellhousing bolt patterns are different.

Rather than the loved 440, do a stroker 318 instead. Rebuild your existing 904 with HD parts (which do exist, to raise the torque capacity) and better clutch/band frictions. The 904 ALSO takes less power to run, than the 727. Put the biggest trans cooler you can fit in front of the radiator/condenser, too. OR use the LA727 for the stroker LA engine.

Doing a stroker LA engine will also mean all of your current stuff will bolt to the stroker motor, which can EASE things a good bit.

Just some thoughts,
CBODY67

 

[Grindhouseproject]

What engine is in the wagon? You will need to address the balance weights on the converter also.

It’s got the factory 360 in it currently.

 

[Grindhouseproject]

Only "light-duty emissions" vehicles got lock-up converters, plus any HO engine cars. So the D350 trans should not be a lock-up converter.

Main issue to me is that if and when you do the RB engine swap, you'll need (as mentioned) a B/RB 727 to bolt to it, as the bellhousing bolt patterns are different.

Rather than the loved 440, do a stroker 318 instead. Rebuild your existing 904 with HD parts (which do exist, to raise the torque capacity) and better clutch/band frictions. The 904 ALSO takes less power to run, than the 727. Put the biggest trans cooler you can fit in front of the radiator/condenser, too. OR use the LA727 for the stroker LA engine.

Doing a stroker LA engine will also mean all of your current stuff will bolt to the stroker motor, which can EASE things a good bit.

Just some thoughts,
CBODY67

Yeah it’s a non lock up. And if I was a smart man I would build a small block but my realization lately is I’m a bit of a masochist. I probably should just go through the 904 and get it working

 

[Big_John]

Yeah it’s a non lock up. And if I was a smart man I would build a small block but my realization lately is I’m a bit of a masochist. I probably should just go through the 904 and get it working

I think the question to ask is "how much weight are you going to tow?" and "when do you want (or if you want) to change to a big block?".

If you are just going to two a small trailer, a good 904 will do the job without any problems. A heavy trailer, like let's say a car hauler, would be better with the 727.

Changing to a big block will mean a 727, but the small block 727 isn't going to bolt up to the big block.

A 360 is a decent motor to tow with. Again, how much are you going to tow? A change of rear gear might be a more logical change. 3.23 is a nice compromise and 3.55 if you are doing a lot of towing.

 

[Grindhouseproject]

Mostly probably gonna be towing a open car trailer with my big block 70 dart.I’m was planning on swapping 3:23 in at some point. And I am aware that the bell housing bolt pattern are different from SB to BB I figure If I do throw in the 727 now when I find a big block and trans I won’t have to mess around with the driveshaft and linkages then. Don’t know if the most logical thought process

 

[Big_John]

Mostly probably gonna be towing a open car trailer with my big block 70 dart.I’m was planning on swapping 3:23 in at some point. And I am aware that the bell housing bolt pattern are different from SB to BB I figure If I do throw in the 727 now when I find a big block and trans I won’t have to mess around with the driveshaft and linkages then. Don’t know if the most logical thought process

Then it makes sense to do the trans swap, but I don't know as it's logical to do it with the small block if you are going to be changing to a big block. As I said, the 360 isn't bad for towing, especially with a gear change.

I knew a lot of guys that used 318 engines back when we towed race cars with big cars rather than trucks. I used a '70 Sport Fury GT and then a '73 New Yorker myself with a Bock trailer. But that was in the days when we had to shoo the dinosaurs off the track before we ran.

So... Now you have to post a picture or three of the Dart as we are all picture junkies that live vicariously through other's adventures.

 

[MAXWEDGECHAR]

I think truck linkage is different. I seem to remember trying to put a pick-up big block 727 into my '77 400 Newport and the linkage was different I think.

 

[CBODY67]

I think truck linkage is different. I seem to remember trying to put a pick-up big block 727 into my '77 400 Newport and the linkage was different I think.

Just change the complete set-up, rather than seek to adapt one to the other, I suspect. They both do the same thing as the throttle pulls the same direction, I suspect. It might be that where the throttle rod adjustments happen to be (and how they happen) is the main difference.

 

[MAXWEDGECHAR]

I have also done the opposite. I swapped a 904 into where a 727 was in my '68 318 Custom Suburban 50 years ago. I have a parts catalog collection. I forget all the cars that used the same length drive shaft. I haunted junkyards for a month. I finally went to a dismantling yard that had racks of driveshafts. The guy at the counter asked if I brought my old one. I told him, no but I brought my tape measure! And there on one of the racks was a driveshaft marked "1968 Plymouth Station Wagon Auto", the right length!

 

[Grindhouseproject]

Then it makes sense to do the trans swap, but I don't know as it's logical to do it with the small block if you are going to be changing to a big block. As I said, the 360 isn't bad for towing, especially with a gear change.

I knew a lot of guys that used 318 engines back when we towed race cars with big cars rather than trucks. I used a '70 Sport Fury GT and then a '73 New Yorker myself with a Bock trailer. But that was in the days when we had to shoo the dinosaurs off the track before we ran.

So... Now you have to post a picture or three of the Dart as we are all picture junkies that live vicariously through other's adventures.

Just pulled the slant and 904 from the dart putting in a 383/727 and a Dana 60 with 3:73s

 

[lemondana]

Is it a factory 360 car? I'm pretty sure they didn't put 904's behind 360s in C Bodies till 74 I think. And then they were the HD 999 trans. Get the PK part number off of the pan rail right under the shift linkage and post it here. If if would be the 999, I would rebuild what you have. There wasn't a 4 bbl swap on the 360-was there? Post some pictures of your kickdown linkage and throttle bracket. I have the 999 part numbers.

 

[lemondana]

I would think that Ma Mopar would put the 727 in a big wagon. I don't know that for a fact though.

 

[413]

they made wagons with 360 and 904, I had one

 

[Grindhouseproject]

I would think that Ma Mopar would put the 727 in a big wagon. I don't know that for a fact though.

Well my silly little 20 year old brain decoded the fender tag when I got it 2 years ago. D34 said light duty trans and I just ASSUMED that was a 904 but after looking at it…. I think it’s a 727