Replace heads or 4.0??

[aintskeered]

Hey guys,
I am new here and I just bought a 1988 Ranger 2.9l that needs heads. It’s a manual, has 467k miles. Im trying to decide if it’s worth it to replace the heads or go with a 4.0 swap.

It’s got a 6 inch suspension lift, 3 inch body lift and 35s on it so I’m sure it’ll be a slug once running.

I am a little worried about power as I live in colorado and going west there are a few passes.

Any info would help a lot thank you.

 

[PetroleumJunkie412]

Heads.

Hands down.

Probably due for pistons as well.

Guaranteed cam is shit at this point, too.

 

[Shran]

Heads.

Hands down.

Probably due for pistons as well.

Guaranteed cam is shit at this point, too.

Sounds like you're suggesting a set of 4.0 heads on a 4.0 block

 

[alwaysFlOoReD]

At close to half a million miles it will need a full rebuild including a bore job. Price out the difference between the 2 options....

 

[PetroleumJunkie412]

Sounds like you're suggesting a set of 4.0 heads on a 4.0 block

I'm going back to lurking a Turkmenistani bodybuilding forum.

 

[Shran]

I'm going to keep making empty threats

Fixed it for you

In all honesty I think either option is fine. I love 2.9s and I would concur that it deserves a full rebuild at this point. $$$. A 4.0 swap is probably cheaper and will make more power but the wiring is more work. You can make up for the lack of power in the 2.9 by using deeper gears in the axles.

One thing to consider is engine mods during your rebuild. PJ can give you more details than you need about that but a 2.9 ECM uses speed density and is therefore less friendly to engine mods... a 4.0 will respond better to hotter cams, higher compression, etc withOUT a tune since it uses mass air calculations. So if you rebuild your 2.9 with some speed parts you may need to factor in tuning equipment.

 

[rusty ol ranger]

Get a hold of @PetroleumJunkie412 and ask him how to build a 2.9. Swap in some 4.56 gears and enjoy the ride.

Everyone does the 4.0. Dare to be different. I love the 2.9 and you will to once you get a fresh rebuild and some power parts.

Oh and one tip....swap in the 4.0 radiator (it bolts in)...the 2.9 is a tough little bastard but you have to keep it cool.

 

[Blmpkn]

If you wanna be different you'd swap in a vw vr6 motor. One of the few 6cyl motors that sounds cool.

 

[ecgreen]

This is one of the oldest philosophical dilemmas in the history of western civilization. Very little progress has been made in the last few thousand years. I too have spent my time pondering this issue

 

[ecgreen]

As far as power with those tires and gears, I don't see the 4.0 helping all that much in the mountains. Need gears or smaller tires. With that said, the 4.0 would be better on the hills, but it will still struggle I bet

 

[rusty ol ranger]

Honestly a warmed over 302 would pry be the best option under his circumstances.

 

[RumPunch]

No time on the road yet but just finished redoing my 2.9. .020 over, new cam, new 89+ heads, all internals polished crank, oil pump, injectors, rockers, aluminum Champion Radiator you name it new I am pretty sure parts and labor at machine shop I was around $2500. Could try and add it all up but then I’d cry. Hoping that number helps you plan.

 

[gaz]

aintskeered,

These 2 engines are so similar but so different.

Of the similarities, they both respond VERY well to:
- better flowing exhaust
- headers
- a little extra compression
- lose the crank shaft driven fan and clutch
- tip top functional cooling system

To get more compression with the 2.9L, use Ford 2.8L flat top pistons and up to 0.035" mill on the heads.

To get the same compression improvements from the 4.0L (with up to 94 series heads), use Ford SOHC 4.0L flat top pistons and up to 0.035" mill on the heads.

Neither set up will require tuning if used with 94 or older computers (86 to 91 2.9L or 91-94 ohv 4.0L).

Both engines appreciate not spinning that archaic fan and clutch, using an electric fan or set of them instead.

Using a better flowing exhaust with headers and no crank driven fan and 100% stock engine made the passes a breeze with my 2.9L. The same engine rebuilt with a balanced bottom end, flat top pistons and flow bench port/polish heads/intakes, the overall driving experience was so much improved, that it's hard to explain in words.

I can assure you that rebuilding your 2.9L will cost less in the end as I have rebuilt both the 2.9L and am currently finishing up a 4.0L.

• The replacement parts for the 2.9L are REMARKABLY less expensive
• no rewiring needed
• the 2.9L will get better fuel economy than the 4.0L...no matter what
• for serious off road intensions, I am inclined to agree with Rusty, a built 302 or 5.0L can deliver a new plateau of power.

In summary,
* rebuilding a 2.9L with flat top pistons and a free flow exhaust without the crank shaft driven fan/clutch will be an incredible improvement. [25 to 33 mpg are reasonable]
* swapping in an ohv 4.0L will cost more, use more fuel and be require more effort but will provide more power and torque and a non adjustable valve train. [22 to 28 are conceivable]
- the primary reason I suggest this will cost more is to achieve the same level of reliability from the ohv 4.0L as the rebuilt 2.9L, it will also require a rebuild and subsequently use more fuel.
* a mid size truck/SUV with a stock v8 isn't much improvement but a BUILT V8 is a HUGE difference in power. I've never made more than 24 mpg from any V8.

 

[ecgreen]

aintskeered,

These 2 engines are so similar but so different.

Of the similarities, they both respond VERY well to:
- better flowing exhaust
- headers
- a little extra compression
- lose the crank shaft driven fan and clutch
- tip top functional cooling system

To get more compression with the 2.9L, use Ford 2.8L flat top pistons and up to 0.035" mill on the heads.

To get the same compression improvements from the 4.0L (with up to 94 series heads), use Ford SOHC 4.0L flat top pistons and up to 0.035" mill on the heads.

Neither set up will require tuning if used with 94 or older computers (86 to 91 2.9L or 91-94 ohv 4.0L).

Both engines appreciate not spinning that archaic fan and clutch, using an electric fan or set of them instead.

Using a better flowing exhaust with headers and no crank driven fan and 100% stock engine made the passes a breeze with my 2.9L. The same engine rebuilt with a balanced bottom end, flat top pistons and flow bench port/polish heads/intakes, the overall driving experience was so much improved, that it's hard to explain in words.

I can assure you that rebuilding your 2.9L will cost less in the end as I have rebuilt both the 2.9L and am currently finishing up a 4.0L.

• The replacement parts for the 2.9L are REMARKABLY less expensive
• no rewiring needed
• the 2.9L will get better fuel economy than the 4.0L...no matter what
• for serious off road intensions, I am inclined to agree with Rusty, a built 302 or 5.0L can deliver a new plateau of power.

In summary,
* rebuilding a 2.9L with flat top pistons and a free flow exhaust without the crank shaft driven fan/clutch will be an incredible improvement. [25 to 33 mpg are reasonable]
* swapping in an ohv 4.0L will cost more, use more fuel and be require more effort but will provide more power and torque and a non adjustable valve train. [22 to 28 are conceivable]
- the primary reason I suggest this will cost more is to achieve the same level of reliability from the ohv 4.0L as the rebuilt 2.9L, it will also require a rebuild and subsequently use more fuel.
* a mid size truck/SUV with a stock v8 isn't much improvement but a BUILT V8 is a HUGE difference in power. I've never made more than 24 mpg from any V8.

Awesome post!

So when you rebuilt your 2.9, what did you do for block machining? Magnaflux I am sure, but what else? Line honing, deck leveling, etc? I am thinking of rebuilding a block I have laying around and I have a lot to learn.

As for offroading, it really depends on what you want to do. I wheel a lot in fairly difficult terrain. I have the 2.9 BII and a 2.7 2015 Tacoma. I really have never wished I had more horsepower. Now gearing, traction and line choice...that is important. The only time I might want HP is trying to get through a mud hole, but even then, thats what my winch is for. If you want to rip tires up an obstacle, that's fine (and I get it), but all you are going to do is break stuff. If you are at that level, build a truggy or a rock bouncer. I go as slow as possible and as fast as necessary. High HP is just not needed for difficult-level average guy offroading IMHO. You do get better torque with those higher HP engines, but you can make up for all of that with gearing. I'll take a simple low HP engine, gearing and a doubler any day!

With all that said, V8s sound cool and I get it lol. Also, I bet a 302 at the end of the day would be more reliable long-term, but I am just guessing with that.

 

[aintskeered]

aintskeered,

These 2 engines are so similar but so different.

Of the similarities, they both respond VERY well to:
- better flowing exhaust
- headers
- a little extra compression
- lose the crank shaft driven fan and clutch
- tip top functional cooling system

To get more compression with the 2.9L, use Ford 2.8L flat top pistons and up to 0.035" mill on the heads.

To get the same compression improvements from the 4.0L (with up to 94 series heads), use Ford SOHC 4.0L flat top pistons and up to 0.035" mill on the heads.

Neither set up will require tuning if used with 94 or older computers (86 to 91 2.9L or 91-94 ohv 4.0L).

Both engines appreciate not spinning that archaic fan and clutch, using an electric fan or set of them instead.

Using a better flowing exhaust with headers and no crank driven fan and 100% stock engine made the passes a breeze with my 2.9L. The same engine rebuilt with a balanced bottom end, flat top pistons and flow bench port/polish heads/intakes, the overall driving experience was so much improved, that it's hard to explain in words.

I can assure you that rebuilding your 2.9L will cost less in the end as I have rebuilt both the 2.9L and am currently finishing up a 4.0L.

• The replacement parts for the 2.9L are REMARKABLY less expensive
• no rewiring needed
• the 2.9L will get better fuel economy than the 4.0L...no matter what
• for serious off road intensions, I am inclined to agree with Rusty, a built 302 or 5.0L can deliver a new plateau of power.

In summary,
* rebuilding a 2.9L with flat top pistons and a free flow exhaust without the crank shaft driven fan/clutch will be an incredible improvement. [25 to 33 mpg are reasonable]
* swapping in an ohv 4.0L will cost more, use more fuel and be require more effort but will provide more power and torque and a non adjustable valve train. [22 to 28 are conceivable]
- the primary reason I suggest this will cost more is to achieve the same level of reliability from the ohv 4.0L as the rebuilt 2.9L, it will also require a rebuild and subsequently use more fuel.
* a mid size truck/SUV with a stock v8 isn't much improvement but a BUILT V8 is a HUGE difference in power. I've never made more than 24 mpg from any V8.

Thank you!! That helps more then you know.

I'll definitely look into doing flat top pistons and an electric driven fan. I may look into a 4.0 radiator if that would help. (how do I go about that?)

I am pretty worried about MPG (I'd rather not take the lift or tires off) so if that helps that would be huge.

I do have the chance to buy a 83 Mustang with a running 302 in it for pretty cheap so I'm curious what the input is on that.

The plan is to do a cross country trip in a few months for work so I am building a camping setup. Would the 302 be better with all the extra weight? Or should I stick with the 2.9, flat top pistons, etc.