Alright, so I'm just getting out of a geo tracker, want something more capable.
My priorities are:
Reliable
Easy to fix and find parts
Mpg (I understand it's limited in a truck) how big is the difference between the three in a regular cab 4x4?

I'm heavily leaning towards a 4.9, I doubt my towing is gonna go over 3000 pounds. Are the 5.0/5.8 worth considering? I sometimes see hear the 4.9 actually sometimes gets worse mpg

 

Best i get out of my 4.9 here in the mountains is 15mpg unloaded. With that said I chose it over a 5.0 for pulling a trailer with my lawn equipment on it. Now that I have my IDI truck I no longer use it for that. I would wager that if you are curious about parts that the 5.0 is probably more plentiful in pick-a-part/junk yards. For me ease of working on is a toss between the 3. Ive been searching for an extended cab truck with a 5.8 and have decided its almost impossible to find one rust free.

 

Any one of those will get 8 or 18mpg depending on transmission, rear gears, tire size as well where and how you're driving.

If you care about fuel economy skip the 5.8 and accept that you will be going up hills slightly less quickly. Toss a massive transmission cooler on whatever you get (assuming you get an auto). Get whichever truck is in better condition. Most of these trucks have really tall gears so if you can find something that's 3.55 or 3.73 go for it.

Most discussions about the 4.9 vs the 5.0 and about fuel economy in general are really high level discussions in which a large fraction of the participants know little about the subject and rely primarily on anecdotal experience to back up their claims (welcome to the Internet) and are about as useful as reading reviews on Amazon. Either engine will get the job done.

The 5.0 does seem more plentiful in junkyards but pretty much all the sub-$1k trucks on CL that mover under their own power are 300s. There's a lot of 300s out there.

 

I haven't had an auto in three years, and I'm not getting one now. Of the top of your head, do you know how to tell the gear ratio? It's stamped on the differential right? Or is it in the glove box?

 

Axle code on the door-jamb sticker or read the tag bolted to the diff.

 

If its a manual you want, then your best bang for the buck would be an F150 with the 300 or the 302 with 3.55 gears. They didn't put a manual behind 351's on F150's only the bigger brothers got them.

My 94 302 5 speed with 3.55's gets about 13-14 mpg on average. It has had a recent tune-up and had all the fluids changed within the last 5000 miles. I also replaced the stock air box with a K&N cone filter. She's running strong about to pass 200k miles. The 300 will give you slightly less power, slightly better torque in a very narrow rpm range, and possibly 2-3mpg more.

Axle code 19 is 3.55 Gears. If it says H9 it will have a factory limited slip in the rear.

 

I have a 1994 w/80k mi, 4.9L, manual, 3.55 gears, short bed, reg cab, 2wd, and I usually get 14-16 mpg.

I had to replace the rear leaf spring brackets as soon as I got it which seems like a common rust issue on this body style

 

4.9. there are so many many of them. ive got 210,000 miles on mine and it still doesnt use oil, have had the tranny rebuilt, at 20,000 miles, but thats it.

 

f150 - 300,straight 6 - (trans of your pref) - 3:08 gears. - this is the ideal 8th or 9th gen truck for you.the more you alter from this,the less ideal you'll be for your use.
go with 2wd if you can.better mpg.go with 4wd if you need it.

that was easy.next.


side note; i wouldn't pass up this combo sporting 3.55 gearing instead (i personally much prefer them over 3.08's).it just that,since your priority list is mpg and performance isn't listed,it's the clear winner for the amount of weight you plan to tow.

 

Many thanks folks. I actually found this 1990 150 with 150k miles. For $2000. 5.0 manual. Seems like a good deal, but we'll see. Is there any non obvious problems to look for on that specific motor?

 

How about a pros/cons list?

Engines
4.9L 300 L6
Pros: Bulletproof design, better fuel economy than a V8
Cons: Certain repair procedures are difficult, some parts are hard to find

5.0L 302 V8
Pros: Very reliable, great HP and torque curve, high parts availability
Cons: (Again) Some repairs are difficult, "meh" fuel economy

5.8L 351 V8
Pros: Same as 302, better performance numbers when modified
Cons: Lower fuel economy

No matter what engine you get, change all the fluids/filters and check all the systems for proper operation.

Transmissions
Automatics: There are three different models that a Bronco could have: AOD, C6, or E4OD. When upgraded and maintenance is done on time, the E4OD is the best overall as they used this as a base for the Super Duty transmissions later on. AOD and C6 are good overall, but the C6 only has 3 speeds, versus the E4OD which has 4 speeds and a locking torque converter. If you get an auto, change the fluid no matter what the previous owner said, change the filter/pan gasket as a kit and flush the cooler.

Manuals: Some will say manuals are better than autos (I disagree) but they are highly sought after. If you want to tow heavy stuff easily, get an auto. Manuals are more fun to drive and less can go wrong than on an auto. Again, change the fluid and inspect the clutch system.

4x4 or 2WD?: A 4WD truck will weigh more and lower fuel economy, but you can go almost anywhere. 2WD are mechanically simpler and lighter, but without upgrading the axle, avoid the trails or you'll probably get stuck.

 

Ahh the torque monster myth. Here's an engine information sheet, straight from Ford for 1990.


260 ft lbs at 2000 RPM for the 4.9L
270 ft lbs at 2400 RPM for the 5.0L
315 ft lbs at 2800 RPM for the 5.8L

The 4.9L, at no RPM on the dyno charts, ever makes more torque than the 5.8L and is pretty close to the 5.0L torque curve. Must be the peak of 2000 RPM that gets people excited?

 

I see it has rear wheel rot already. You could probably talk the seller down. Around here, $2k has been putting you into a 351W/ZF5/4x4 between 150-200k, mostly supercab trucks (just looked, been a couple months, prices are going up..). I would call that a $1500 dollar truck at best. Needs tires, windshield, body is rotted. It needs 4x4 lockout hubs ($100) because the auto's will fail in very short order if you need 4x4. Guess that's one thing it has going for it, the owner clearly never wheeled the truck. When was the clutch last replaced? Brakes?

Check carefully for more rot. Understand that if you can see the rear wheel arch rot, it's much more extensive than you think because it rots out from behind. The radiator core supports tend to rot, same with rear leaf springs hangers. Can you work on these trucks yourself? If not, you need to be extra picky.

 

He recently told me it was painted. Maybe that's a red flag? Where does the rust start, on the edge of the rear wheel wells?

 

The real answer is; whichever truck you find that is in the best condition regardless of the engine.

351w getting worse mileage than a 5.0 is a myth.