84 351w swap into a 72 mustang

Does anyone know of the 84 351w will fit into a 72 mustang that originally had a 302 w ? I sent a rod out the block the other day and want to put a 351 into it can anyone help me out

ajt 72 mustang said:

Does anyone know of the 84 351w will fit into a 72 mustang that originally had a 302 w ? I sent a rod out the block the other day and want to put a 351 into it can anyone help me out

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Yes, several members of the forum have 351W in their Mustangs. @mrgmhale has a beauty of a 73 Mach 1 powered by a 351W-based engine.

I have a 351w in one of mine. I used the motor mounts and exhaust designed for a 71-73 with a 302. The exhaust sits up a tad higher than it was designed, because the taller deck height of the 289/302 block.

The only other caveats I can think of would be from the different changes they made to the windsors over the years. There are different deck heights and dipstick locations. After the 70s oil crisis, the deck height was raised even higher, which would bring your exhaust up closer to the floor. And a dozen different timing covers, accessory pulley arrangements, etc. You'd want to make sure you put together a collection of parts with a front sump oil pan and all the water pump and accessories all fit and worked together.

giantpune said:

I have a 351w in one of mine. I used the motor mounts and exhaust designed for a 71-73 with a 302. The exhaust sits up a tad higher than it was designed, because the taller deck height of the 289/302 block.

The only other caveats I can think of would be from the different changes they made to the windsors over the years. There are different deck heights and dipstick locations. After the 70s oil crisis, the deck height was raised even higher, which would bring your exhaust up closer to the floor. And a dozen different timing covers, accessory pulley arrangements, etc. You'd want to make sure you put together a collection of parts with a front sump oil pan and all the water pump and accessories all fit and worked together.

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Could I use any of the parts from my 302 to solve any of those issues

To start, you'll need a front sump pan and pickup for a 351W. If your block has the dipstick hole in the driver's side pan rail, it'll need to be blocked off.

The motor mounts and everything to do with the transmission will bolt right up.

You can use the 302 exhaust manifolds, but the Y-pipe (if you have single exhaust) may need to be modified to accommodate the extra width and height of the 351W.

I would take everything off the front of the 302, timing cover included and bolt it onto the 351W. That'll give you the correct dipstick location and ensure compatibility with the 302 pullies and accessory drives. Everything from the 302 should bolt up fine. If you have P/S, you will need to get a 351W power steering bracket. It's a one year only part used on the 1970 Mustangs, Cougars and full-size Fords. Stamped ID number is D0AA-3C511-D, part number is D0AZ-3C511-A

https://www.mustangtek.com/bracket/D0AA-3C511-D.html

NE Performance Mustang in NH shows they have one.

https://neperformancemustang.com/catalog/product_info.php?products_id=2083&currency=USD

ajt 72 mustang said:

Could I use any of the parts from my 302 to solve any of those issues

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I'm not 100% sure on all the details of the 80s 351w and which one specifically you have.

I want to say you could use the oil pan off your 302. We know that one fits in your mustang. If your 351w has the dipstick on the side by the exhaust, then use the dipstick from your 302 as well. You may also be in it for a new oil pump, pickup, and gasket if you're swapping pans.

I'm fairly certain your accessory brackets from the 302 will not work on the 351w. The taller deck height means the holes in the heads are in a different position relative to the water pump. Any bracket that mounts to both the water pump and the cylinder head will be different from a 302 to a 351w. If you've got a truck 351w, some of them had some really wide accessory brackets. They will usually fit in our mustangs, but look terrible. Check and see if your 351w has this bracket on the front of the passenger side head for the alternator. https://secure.cougarpartscatalog.com/d1oe-10a336-ab.html That may let you use some of your existing alternator mounting hardware.

Or, maybe now's the time you bite the bullet and go to aftermarket accessory brackets. I'm about to put the CVF Racing set on mine.

I would say plan on using the timing cover from the 302, since it has the dipstick hole and it is designed for the clockwise water pump. I would just buy a new water pump at this time, making sure it is clockwise rotation.

Sheriff41 said:

Yes, several members of the forum have 351W in their Mustangs. @mrgmhale has a beauty of a 73 Mach 1 powered by a 351W-based engine.

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Yes, our 73 Mach 1 definitely has a 351W in it. The prior owner replaced the original 302 2v when it had a distributor drive gear on the camshaft get in a fight with the distributor driven gear. I am not sure of the extent of things he had to change, but if nothing else it looks like it was a nice installation. He had the 351 that came our of a 1989 F-150, and used rthe heads from a 1969 351W 4v, which apparentty was done more for the compression ratio as opposed due to larger ports. If you want or need (track racing at very high RPM) larger ports you are better off moving into a 351C, as their ports are humongus in comparison. He had the engine built for moderate street/strip performance, although the forged aluminum pistons are only 9.5:1 so the engine could run on 89-90 octant alcohol free fuel. The exhaust valve seats are hardened to help deal with the lack of lead in the fuel. Once built and fired up the engine put out a respectable, and very streetable, 360HP on a dyno.

The HP would have done little to really get the Mach 1 to behave in a spirited manner had he not replaced the ultra-steep rear axle ratio gears (2.79:1) using a 9" gear set and housing with a 3.5:1 TractionLok ratio gear set. In order to recapture some of the vehicle's top end potential, and to slow down the engine RPM at highway speeds, I replaced the C4 with an AOD tranny. If you have a steep rear axle gear ration (2.79:1 oe even 3.0:1) your performance is going to be hampered no matter how power the engine is. I found the 3.5:1 rartion is an excellent compromise, although with the AOD I could have gone even lower (4.11:1) and gotten plenty reasonable results for a comfortable level of performance on the street.

Back to the size difference between a 302 and a 351W, the deck is about 1/2" higher on the 351W compared to the 302. That means some parts you need will be specific to the 351W, whereas a lot of other parts can be shared from the 302 (not a Boss 302!). The intake manifold is one such part where it must be specific to the 351W engine. Despite the ports in the 351W heads not being anywhere near as large as with the 351W heads, the 351W engines can be built up to become scary powerful. Ours is powerful enough to satisfy my desire for a responive vehicle when I flip open the throttle. If you want a car to run on a track competitively, however, a 351C is likely the better bet.