[9Dark6]

Hey guys,

I have a 95 YJ with the 2.5L fuel injected 4 banger and AX-5 Transmission, NP231 transfer case. The transmission grinds in every gear so I'm fairly sure the syncros are shot and it needs a rebuild, this is my first jeep and I've already read that the ax-5 isn't worth rebuilding. I use the jeep mainly for hauling feed from town and rambling around fields. It's not a highway driver or commuter vehicle. Sitting on 3-4" lift and 33's.

I have an '87 F150 with a 300 I6 EFI engine and automatic tranny, I also bought a early '80's Ranger with a 351M carb engine and a NP435 tranny with a NP208 transfer case for donor vehicles. I'm trying to figure out which set up will work best. I'm a ford man so I'm not interested in a Chevy power plant and I would prefer to work with what I already have.

I've read that the 351M is a PITA to put in the YJ due to clearance with headers and possibly top end as well? I understand they engine is a crap engine stock, but this one was modified years ago and used to make decent power. I have all the parts to drop the 351 in if it would fit and an carb would be easier to hook up but overall I don't think it will work from what I have read, or has anyone here done it? Issues I will have with this engine is:

1. It's going to need a new carb, the Holley it has is shot, and I don't think I can even rebuild it.

2. Being that the engine was modified I'm not sure what changes were made to it as far as bore and such, so rebuilding may be a nightmare.

I'd prefer to drop in the 300 I6 mated to the NP435 here are some known issues/questions I have about this:

1. First off comes the debate of the engine being to long. From what I can tell my 300 I6 is the same length as the 4.0L I6 that comes in jeeps so the only issue is likely the water pump clearance. I've read other sources that also report the engine length is the same, I just can't remember if this is block length alone or overall?

2. I know I will have to make my own motor mounts but I'm wondering if I can use the ones that NOVAK offers for Ford engines.

3. From what I am reading, the fuel pump PSI need to be about the same when using EFI. From what I can tell the 2.5L jeep fuel pump should work with the 300 I6 as they seem to have similar PSI tolerances, but if anyone knows for sure that would be helpful? connecting fuel lines might be an issue.

4. I will have to source a bell housing and associated components since the 351M has a differnt bolt pattern. Also the 351M flywheel will be weighted different I believe so it would be better if I could get parts from a 300 I6. I'm also trying to find year that has a hydraulic clutch so that I can possibly use the master/slave cylinder from the donor.

5. I've read that the stock jeep radiator isn't enough to support a bigger engine? One source said that a '65 mustang radiator would work, I'm not sure I believe that since it's such a small radiator(I rebuild '65 mustangs and I have a spare radiator in my shop". Novak sells a radiator but the dang thing costs more then I paid for the whole donor truck. anyone know of a good radiator to drop in with a Ford engine? I know it largely depends on the port locations. Is there any reason I can't just fab in my 300's radiator?

6. Driveline shouldn't be an issue, I have a driveline shop that can build me a shaft If I need it.

Any input you guys have would be greatly appreciated, especially if anyone has done this swap. No matter which engine I use I will have to rebuild it. I'd rather the 300 but whatever is easiest is prolly my best bet.

 

[Awesome]

@mustanggarage does this.

 

[Chrisnvegas]

The Ford inline 6 has nearly 300 ft lbs of torque. It's an industrial duty engine that normally outlasts the vehicle it is placed in.
It's rated #4 of the 10 best engines of all time by several magazines.

"The 300 I6 supplied power for everything from woodchippers and generators to tractors and dump trucks"

"Ford 300 I6 engines have been known to last up to 300,000 miles with no major issues. They produce gobs of low-end torque, including an impressive 265 ft.-lbs. of torque in some instances. That has made the Ford 300 I6, particularly the versions with a forged crank and high-flow exhaust manifold, a popular choice for heavy-duty commercial trucks.

Fun Fact
If you've ever received an on-time delivery from UPS, you likely have the reliable Ford 300 I6 to thank. The Ford 300 has been used on those brown UPS delivery trucks for years."

What else do you need to know?

https://www.onallcylinders.com/2014/01/22/top-10-engines-time-4-ford-300-i6/

 

[4Low2G0]

I'd go with the 300 six, it will be easy to work on. it's already fuel injected and for a ranch/farm truck the torque will be great, also likely use less fuel than the 351.

 

[Chrisnvegas]

I'd go with the 300 six, it will be easy to work on. it's already fuel injected and for a ranch/farm truck the torque will be great, also likely use less fuel than the 351.

I agree except...
He'll probably never have to work on it. :laugh:

 

[11-11-11]

Swap in the 300's radiator. Sounds a fun project. Keep us posted!

 

[9Dark6]

Haha, thanks for the input guys, the 300 is a dang good motor, that's why I was leaning towards it more. I looked at Mustangs profile but I couldn't see any write ups on dropping a 300 in if he has one some place? Am I going to have issues with the PCM I have since it's for an automatic? I've also got to figure out how much of the emissions crap I can delete

 

[4Low2G0]

I believe the 87 AOD auto trans was not computer controlled so your ECM should work.
You'll need to keep the O2 sensors and if there is one behind the cat that will have to stay as well, if not the cat can go.
87 should use Fords EEC IV engine control system, Google is your friend here.

If you're in an area with emissions testing, there may be a problem with the engine being older than the chassis.

 

[Galligher]

Sorry to be the bearer of bad news, you may want to rethink both.

The 300 six is a great engine, but you need to measure. 300 cubic inches (4.9 liters) in a straight six will be long when compared to the AMC/Jeep 4.0. I am not saying it "will not" fit, but you need to account for waterpump snout sizes, pulley lengths, fan, radiator, etc... The vehicles the 300 went into generally had more engine bay space than a wrangler.

I would stay away from the 351M. If it were a 351W or a 351C, different story. The 351M and 400 were bastard engine families that do not have a following. Ever heard of a Boss 302 or Boss 351 from the 1969-1971 Mustangs? They essentially had a Windsor style block with Cleveland style heads. These were great performing engines as the 351C heads were great for the era. The 351C 2bbl heads were great street heads and the 4bbl heads were pretty much race ready from the factory. The Windsor was the better block based on journal sizing, but the Cleveland had the heads which again is a Boss engine. The reason I state this is the 351M was the opposite of the Boss. It had a Cleveland style block with Windsor style heads. Boss=Good 351M/400=Bad for performance for the weight and size of the engine. To be honest, an older 5.0 (Windsor family, not a Coyote) would be a much better bet in the Ford family. I have worked on Windsor, Cleveland, and Modified versions of the 351 years ago when all were much more prevalent. You can find aftermarket heads to make a 351W perform, but factory GT40P heads or the E7's work well on a 5.0. If you are going to go through the work to install a v8 (it is much work), rethink the 351M. Also, part availability would be much better for a Windsor family.

I went the easy route and swapped a 330hp GM Votec 5.7 crate engine with a 700r4 trans into my Wrangler. I really enjoy it, but miss the stick.

 

[Galligher]

Just a couple of more notes after re-reading your post, sounds like you may already be aware of the whole 351M family:
-I have to believe the 300 would be longer than the 4.0, but maybe bore spacing was big on the 4.0? I ran out of space on the front with fans, running a low profile SPAL fan now. You won't have to deal with an HEI and firewall though.
-Consider where the exhaust will come down when compared to the front driveshaft. I can't imagine 351M/400 manifolds/headers are easy to find, you may run into issues if they have heat riser incorporated into the manifolds like many vehicles did during the 70's/early 80's. I am now re-doing my y-pipe as I did not like how close it was to the driveshaft and oil pan initially.
-You may not want to spend the money, but I am now running a Holley Sniper EFI. I love it. I had a good quadrajet on it, but the Sniper system is too easy. I know I am keeping all my hp/torque with a poorly tuned carb or factory efi for sbc's (Ford 5.0 EEC IV would be good here). You would have no need for it with the 300. Walbro fuel pumps are fairly universal and I am running one in place of the previous 4cyl pump. I have a return style fuel injection with the Sniper and the YJ tank is also plumbed this way. As long as you have enough pump, I think you would be good if the engine you pick with FI is also a return style.
-Make your own mounts or by weld in ones. The other option are the mounts that are adjustable, I didn't go that way as I didn't know if the hp I wanted to eventually puch would break it. Adjustable mounts would be interesting if you wanted to tweak things later. You will want to control height for more exhaust down/y-pipe clearance (v8), but still able to close the hood. Also, if you plan on a mechanical fan, then your radiator and shroud (for a v8 you will need a shroud). If you go electric fan, just account for the distance you need. I finally created something interesting and used a large aluminum baking pan on my aluminum radiator for a fan shroud. Most people don't believe it is a baking pan...
-For your flywheel potential off balances, many years ago my father helped my swap a 1969 351W into my 1982 GT. it was 28oz vs 50oz. He leveled them with weights from a pool ball with string and a level. We removed metal from my 5.0 50oz flywheel till it matched my 28oz flywheel. At first I was very skeptical, but my father worked for DANA corp in many areas so I trusted him. It worked. It was also the late 80's, so Ford swap flywheels were not common yet. I wouldn't spin it 7000RPM, but to 5500RPM it was good.
-For a v8, you cannot have enough cooling. Mustangs, not as big of a deal. In 4WD in lo, the engine is building heat without the wind speed to cool. You need a good cooling system. I would run as big of a radiator as you could. I went the easy way and just bought a swap radiator. Looking back, it would have been better to buy a radiator with side tanks and then fabricate a radiator clamping system like a fox mustang. I run a 16" SPAL pusher and puller fans (offset), transcooler, and a good shroud and it stays cool in hot weather now. Without all of it, I had issues. I think I finally have it right. Again, capacity and airflow via fans if you are going to use it as a Jeep.

A cool Ford engine that I loved was the 2.3T. I had a Merkur XR4ti and an 88 Turbo Coupe. I beat the hell out of those engines and upped the boost to 21psi, ported exhaust manifold, 3" downpipe, and methanol injection cooling with a sprayer pump/pressure switch. The rods and build on those engines were better than the 5.0. Biggest issue was the TFI. That would be an interesting engine for a light wrangler.

 

[Chrisnvegas]

@Galligher
It sounds like he's working with what he's got.
The 300 is 3 or 4" longer than the 4.0 I think it's do-able.

I'm not a fan of the M either. Why they even put that combo together, who knows.
I have the 351C in my Mustang. It makes distinct wonderful sounds (I think it's the firing order) and loves to rev

 

[9Dark6]

Thanks guys, some good info here. Chris is correct, I am trying to work with what I already have if possible. I measured my friends TJ 4.0L and came up with roughly 36" from bell housing face to face of fan blade I'll check my 300 again tomorrow when I am off work. going to try and order the NP435 rebuild kit so I can get that rolling. I'll update as I go. A lot will depend on if the 300 is still good when I tear it down.

 

[mark1305]

I agree with a lot of the comments on both engines. I had a 300 in a 69 Ranchero with a 3 speed manual transmission. Loved it. Had a 400M in a 78 Grand Marquis wagon. Had as much torque down low as a Chevy 454 but only about 185 HP and was a dog (as is the 351M). I think the wagon topped out just over 85 MPH. When I hot rodded that car it got a 460/C6 combo transplanted into it but that's another story.

I vote for the 300 inline six without question.