302 to 351W 69 Coupe. Fact Thread

[Aw4g63]

So, I'm looking to assemble a quick easy searchable thread for this swap.

I searched through about 60 threads and found little "fact". Mostly things like "Well I think you need to do this..." Or "I heard"

The best thread I found was this thread -->351W Swap

So heres the deal, I have a full top to bottom 351W from a 79 F250

I'm going to get it home and asses the things I need to drop it right in. Hopefully I can just re-use all the accessories, swap oil pans and headers and be set.

Anyone have any factual input? I'd like the build a nice resource so this question can be easy answered in the future.

Thanks everyone.

 

[rbohm]

first thing to do is make sure you have a 351w, and not a 351m. the m is more prevalent in trucks. you can tell right away by where the coolant outlet is. if in the intake then you have a 351w, if from the block you have a 351m. the 351m will not swap very well at all.

if you have a 351w then the swap is a virtual bolt in. the bellhousing pattern and the engine mounts are the same. the oil pan from the 302 will not swap to the 351w as the rear main cap seal is much larger than the 302's, and the pan rail is slightly different.

you will need to change a few brackets on the front dress due to the deck height difference between the blocks.

since the 351w was an option in 1969, you can get headers designed for the 351w that fit the engine compartment.

by the way, i believe i have a stock 351w oil pan in my inventory. if you cannot locate one in your area let me know and you can have the pan for the cost of shipping. assuming that i can locate it of course.

 

[Aw4g63]

first thing to do is make sure you have a 351w, and not a 351m. the m is more prevalent in trucks. you can tell right away by where the coolant outlet is. if in the intake then you have a 351w, if from the block you have a 351m. the 351m will not swap very well at all.

if you have a 351w then the swap is a virtual bolt in. the bellhousing pattern and the engine mounts are the same. the oil pan from the 302 will not swap to the 351w as the rear main cap seal is much larger than the 302's, and the pan rail is slightly different.

you will need to change a few brackets on the front dress due to the deck height difference between the blocks.

since the 351w was an option in 1969, you can get headers designed for the 351w that fit the engine compartment.

by the way, i believe i have a stock 351w oil pan in my inventory. if you cannot locate one in your area let me know and you can have the pan for the cost of shipping. assuming that i can locate it of course.

Very helpful sir! I'll look at these things.

He said the engine was from a 79 F250, after a quick google it looks like that is an 400M engine code which I'm assuming is the 351M. What a shame. But good think you told me! Saved me a big hassle.

Hopefully this thread will help others in the futures aswell.

 

[rbohm]

the 351m and the 400 use the same block, which will bolt in place of a 460, which is why the bellhousing wont interchange. start looking under the hoods of mid 80's and later ford trucks as they will have the 351w engine in them.

 

[Rusty67]

You have a 400M... maybe you should just build it. The 400M is a really kewl motor this is overlooked by a lot of people because it is sort of a bastard motor. When built right these motors can get really impressive results. I understand if you don't want to build it up but it would definately be something that not very many people would have under the hood.

 

[bnickel]

the 351m and the 400 use the same block, which will bolt in place of a 460, which is why the bellhousing wont interchange. start looking under the hoods of mid 80's and later ford trucks as they will have the 351w engine in them.

mostly true, some very early 400 blocks actually had the standard small block bellhousing pattern and motor mount location. i think only 71 and maybe some 72 blocks were this way but only the passenger car blocks AFAIK.

 

[Sweeet Ride]

I have just put a 351 Windsor into my '67 Mustang and there are a "lot" of things to change.
I used a March billet aluminum kit .....gave me serpentine belts and all the hardware for p/s, alternator etc....it is expensive but in the long run its your best bet....real quality.
Had to make changes to exhaust....the headers from the 289 bolt right on but they don't line up with your exhaust...its minor but needs to be done.
The biggest problem is with the higher deck height of the 351.....you have to use a single plane intake (they're lower) and a dropped air cleaner base with a 2" filter to even come close to closing the hood.
Thers a few wiring issues but monor....lots of little things.

 

[Sweeet Ride]

Moroso oil pan works very well and there is room for it with the stock steering etc.
Also remember...if you use the March Pulley system (with power steering)...it requires you go to an electric fuel pump.
See their website at :wwwmarchperf.com

 

[bnickel]

The biggest problem is with the higher deck height of the 351.....you have to use a single plane intake (they're lower) and a dropped air cleaner base with a 2" filter to even come close to closing the hood.
Thers a few wiring issues but monor....lots of little things.

ummm, on a 69 you DO NOT have to use a single plane intake. i have an E'brock performer and i know a bunch of people running weiand Stealth, E'brock performer RPM, Victor JR, RPM air gap etc. if you used the original 67 mounts that may have been your problem.

also no wiring needs to be done at all if going from a 302 to a 351.


the biggest thing is the year of the engine or more specifically whether the engine has a 3 bolt or 4 bolt harmonic balancer if it's a 4 bolt balancer then you'll have to make some changes to the accessory pulleys/brackets etc. or you can just swap to a 69 3 bolt balancer and use all of the 302 parts or at least most of them. you'll need a 69 351w specific alternator spacer that bolts into the head and possibly another one for the power steering pump depending on whether or not the car has ac, if the car does have ac you may need some different ac brackets. the exhaust will need some slight modifications to work with the wider windsor engine and that's pretty much it.

67-68 may have other isssues but for 69 it's pretty much a bolt in if you use the 3 bolt balancer.

 

[Max Power]

The main difference in the nomenclature of the two engines is height and width. What you need depends on what you have acquired to put in. If you have a complete engine from another 69-70 Mustang from carb to pan, with all brackets and accessories, you will only need to change the exhaust and radiator, for the most part. If you have just an engine, you will probably need the following things:

1. Either the accessory bracket adaptors from 1969, or pulleys and brackets from a 1970 model.

2. A radiator for a 351 or a water pump from a 302. I believe the water pump exits on the passenger side on the 351 and drivers side on the 302.

3. Z-bar if you have a 4 speed.

4. New exhaust, depending on what manifolds or headers you use.

If you are going with just a short block and re-using heads, the parts that don't interchange have to do with height and width. The 351 is taller and wider, so oil pump driveshaft and pushrods won't interchange. The intake manifold is different. The distributor, I believe, is different. The exhaust manifolds, while interchangable, are different.

The only wiring difference from the factory is firing order, and you may or may not have to change that, depending on what year motor or cam you are running.

It's been years since doing this swap, so I may have forgotten a thing or two.

 

[rbohm]

bnickle, you are right about the very early 400's, but i have not seen any early blocks, truth be told.

sweetride, i have yet to find a single plane intake that is lower than the stock intake, or the performer intake(i have both by the way).

 

[bnickel]

2. A radiator for a 351 or a water pump from a 302. I believe the water pump exits on the passenger side on the 351 and drivers side on the 302.

depends on the year. all pre 70 289, 302 and 351's had the water pump outlet on the passenger side and from 70-up they were on the driver side.

Rbohm, i have seen an early 400 block. a friend in high school had a 71 galaxy 500 with that engine. that's not the only car i've ever seen that had one but that's the only one i ever worked on.