Hi, doing a trans swap on a 78 4x4 f250 and looking for discussion about this swap from the 351M to the 351W and have to change bellhousing and clutch stuff, and trying to figure out what parts I need to change to and whether the W came in our generation of trucks or not, but the M engines with the 4speeds combos we're made into the 80's, so I'm seeing what was available then and hoping these parts will work, as per my thinking that from a production standpoint back then that FORD would try to reuse as many non-visible parts as possible during a body/chassis change.

After ordering and receiving some parts from RockAuto, I notice in the LMC catalog that there was an 11" clutch option for the 302 4speed, and of course I ordered the 10" from RA, which was also available. So in the catalog it lists a bunch of year interchangability, stating 80-82 for 351M in bronco (I'm only using the bronco years because the pickup years only say 351 and dont specify W or M, at least in the catalogs I'm looking in) and 83-86 for the 351W. Will the 10" clutch be okay for an f250 instead of a bronco?(its a single cab long box). I don't plan on hauling anything with it, except an 1600lb camper for a couple weeks of the year.

So about the swap, what I have found:
The W used the same frame mounts as the M so I don't have to change those.
The M's bellhousing is the same as the 460 so I have to change the bellhousing on the transmission to mate up to the 351 W.
I've put a 302 in place of a 460 in the past and I vaguely remember that the 302 sat too close to the firewall BUT that was a 302/FMX auto that came out of a Granada Car, so I am thinking those engine side engine mounts were "spaced" for the cars frame mounts and not the trucks, so I am thinking now that I have a 351W from a 1984 4x4 truck, with truck engine mounts, that the spacing will lineup so that the engine bolts to the bellhousing and is not super close to the firewall like the last time I attempted something like this 15 years ago.

I have a used bellhousing to use.

I have a new LUK flywheel and a new LUK 10" clutch kit with pilot bearing, and new bolts or both.

I figure I should order a new clutch fork because everything will be open and I only want to do this once, and I NEED a new rubber boot for the fork as well, AND I still need to source the bracket the bolts to the back of the engine that has a bushing(?) for the Z-bar part of the clutch linkage, AND I probably should change the bushing on the frame mounted bracket as well so the whole linkage assembly is tight and swivels freely.

I also need a fuel pump block-off plate to delete the mechanical pump as the truck has a propane system that will be retained. Well this turned into a long post lol...

Discuss please! Tell me what I am doing right for parts/swap and what I have wrong so far.

 

302/351w use a few flyywheels 302 uses a 28 or 50 ounce imbalance and switched sometime in the early 80s

​​​​351w uses a 28 ounce

There are also different size flywheels 157 and 164 your bell housing will probably use 164

The starter wont touch the flywheel unless you use the 164 flywheel in the correct bell housing

157 tends to come with a 10 inch clutch 164 uses an 11 usually

I came across a 160 tooth flywheel before so those exist too

You also need the right starter as the ring gear is on the engine side of the 164 and tranny side of the 157 you will eat starters if you use 157 starters on a 164

 

1981 was the first year the 351W was installed in F150/350's & Bronco's.

 

Flywheel is part number: LUK LFW116

I have a 164 tooth flywheel, and the bellhousing is out of an early 80s ford truck or bronco, or maybe a van, but I don't recall hearing of any manual vans. I'm searching to find out what balance this is that I bought, trying to navigate LUKs parent site is a joke, so I'm looking through the re-sellers catalogs for info, talk about making it hard on the purchaser!

 

Thanks ND

 

So update time: I had time and opportunity back then but lacked a couple parts so pulled the truck out of the shop after prepping the engine to pull but leaving it in engine bay. So got the last couple things except the bellhousing bracket for the clutch Z bar, see this: https://www.ford-trucks.com/forums/1...r-bracket.html

Apparently I had the wrong clutch kit and wrong flywheel, so toasted half a day phoning and driving around looking for the correct clutch kit and ended up with the 11" clutch kit and pressure plate from Napa, will find the box for the number if there is one. AND I had a used flywheel that is the correct 50 ounce for my 1984 351W so I had that machined.

Recently pulled truck back into shop and pulled old engine and put all the new clutch stuff on the new engine, changed bellhousing on trans, and got engine lined up and bolted to transmission, went to drop it down and of course the engine mounts didn't drop into the frame perches...

 

Double check, but I think all 351Ws are 28 ounce. They didn't change along with the 5.0, in 1981 or when ever.

 

Guy at the machine shop confirmed that my 1984 351W engine requires the 50 ounce. Theres other threads in this forum that mention this difference too, sometime between 1979 and 1984 the W's got different weights for whatever reason.