4.0 block/spacer/seperator/starter index plate

[vagabond80]

hello folks.

In my '99 2.9, po swapped in a m5od-r1 from a 4.0. I'm about to do the slave/throw-out and put in a new 4.0 clutch, etc. while I'm there.

I have seen reference to this dozens of times on the forums, and yet I'm still not entirely clear.
assuming the plate is still 2.9(which originally had the FM), can this NOT be modified to fit the 4.0 parts with the Mazda trans?
asking because https://www.therangerstation.com/tech/ford-2-9-converted-to-4-0-clutch/ says:
4.0 manual block plate (A 2.9 FM/TK block plate can be used with FM/TK transmissions but will not work with Mazda transmissions. The starter hole must be opened up so the 4.0 starter can fit in 2.9 plates)
Does it imply that with the 4.0 Mazda trans I must already have the correct plate? if what I've got cannot work, does anyone have a part number or even an image or some reference to the right stuff?
searching the different terms online I keep getting the wrong or unrelated parts pushed on me.
I recently had to move to an apartment where I cannot do my own auto work, so I must take it to the shop, and I'm trying to keep things as straightforward as possible for them.

after a talk with a ford parts rep who understood what I was looking for, he believes it should be part fot7-7007-b, but its obsolete and he couldnt confirm it was for the m5od. google yields nothing from that part number.

As usual, I apologize for potentially beating a dead horse, but most threads I've found are rather ambiguous or end with some sort of "I found what I needed" with no explanation for the next guy

 

[Shran]

Just curious why you're asking? I assume that you have a block plate in there now that is working correctly?

Here's my experience...slightly different than yours but maybe relevant:

I have a 4.0 and a C5 auto from an '84 Bronco II. The block plate I used came from either a 2.8 or 2.9 powered truck with an A4LD...part number on it starts with E3xx IIRC. It fits a 4.0 engine just fine, the alignment dowels perfectly but with the trans bolted in place I found that the starter is out of alignment. I had to hog out the dowel holes and rotate the plate for better starter alignment... it was roughly 3/16" off.

I believe I also had to file out the big starter hole just a hair to make my 4.0 starter fit. I am not totally sure about this though as I did it a few years ago.

The main difference between the starters other than the wiring is the size of the big hole. The bolt holes are in the same spot. The main difference between the 4.0 and 2.9 block plates other than the starter hole size is the bottom of it... 2.9 transmissions have two little bolts that hold the plate to the trans, 4.0s have two big bolts that go through the trans and into the oil pan.

 

[vagabond80]

Just curious why you're asking? I assume that you have a block plate in there now that is working correctly?

Here's my experience...slightly different than yours but maybe relevant:

I have a 4.0 and a C5 auto from an '84 Bronco II. The block plate I used came from either a 2.8 or 2.9 powered truck with an A4LD...part number on it starts with E3xx IIRC. It fits a 4.0 engine just fine, the alignment dowels perfectly but with the trans bolted in place I found that the starter is out of alignment. I had to hog out the dowel holes and rotate the plate for better starter alignment... it was roughly 3/16" off.

I believe I also had to file out the big starter hole just a hair to make my 4.0 starter fit. I am not totally sure about this though as I did it a few years ago.

The main difference between the starters other than the wiring is the size of the big hole. The bolt holes are in the same spot. The main difference between the 4.0 and 2.9 block plates other than the starter hole size is the bottom of it... 2.9 transmissions have two little bolts that hold the plate to the trans, 4.0s have two big bolts that go through the trans and into the oil pan.

thanks for the reply
asking because I've purchased all the 4.0 parts for the clutch upgrade, but I don't know if it currently has a 2.9 or 4.0 clutch (previous owner did the m5od swap)
the way I read the wording in the write-up I linked, the 2.9 plate works when modified for 4.0 parts with a FM trans, but not with the m5od. <trying to figure out if my understanding here is wrong

 

[Shran]

Oh I see. Well... the starter alignment is really the only factor here. The 2.9 and 4.0 flywheels are basically identical other than the clutch bolt holes being drilled in different locations. So in theory if you had a 2.9 flywheel/clutch now...and you swapped in a 4.0 flywheel/clutch, it would work just fine.

I read that part differently. My understanding of that is - The 2.9 plate will work with a 4.0 starter on a M5OD as long as you enlarge the big starter hole. But if you use a 4.0 block plate, 4.0 starter, and 4.0 flywheel with a M5OD, it will all work perfectly, other than not looking quite right because the bottom two bellhousing bolt holes on the 4.0 trans don't go anywhere.

Measure your clutch disc when you have it apart... IIRC a 2.9 clutch disc is 9" diameter, 4.0 is 10"

 

[BlackBII]

I've done this swap before, but I can't remember which block plate I ended up using. Probably the 4.0 plate. Here's some pics from this thread

It looks like it'll work to me as long as you get the starter to fit as Shran says

Transmission Swap (FM146 to M5OD) and Complete Clutch Upgrade

www.therangerstation.com

 

[vagabond80]

Good info, thanks guys.
Nearest junkyard is 4 hrs round trip away, and no sure shot on getting a plate without pulling a trans, so I'll take the gamble on the current plate(perhaps with some modification) and find out tomorrow or Friday if it's going to work. Will update.

 

[vagabond80]

I suppose my way of thinking was, although except for 2.9v4.0 starter hole size, perhaps there was an interference issue with the m5od and 4.0 when the 2.9plate is used modified

 

[vagabond80]

the mechanic reports the starter fits(maybe it was already a 4.0 plate), however the starter itself is bad (was a new Remy gold from rockauto). he says it takes several attempts with just clicks, then every now and then it starts just fine. so dead spots maybe, but he did say tapping didnt help.
now i'm off to get a new starter locally, and see if things are fixed

-edit-

starter was fine, there was a low voltage issue due to some funny wiring. the clutch that was in there was the smaller 2.9, with a 2.9 starter obviously, but the mechanic said he made no alterations to the index plate.
I must assume the 4.0 plate was already there from when the 4.0 m5od swap was done.
For the moment, seems all is well.