Any years to avoid?
Thanx
I had a 1983 F-150 that had 150hp 302. That was during the gas crunch of the 1980's. That truck was very slow. It only had a 2bbl too. The 351m's are NOT much better. The 300 is slower yet. But it is ample. I'm not sure what predicament your in, but it's not as simple as going to the dealership and driving each motor and deciding. Some trucks are hard to come by these days. I would say that the 300 is more available. Then the 302. The 351 was very hard to come by in F-150's during the "crunch" years. But of course you can always do a swap. Then these numbers are useless.
As far as mileage is concerned. The 302 will get the best overall. Then then probably the 300 and then the 351. My 1983 got somewhere around 12-13 on the highway with a AOD.
The 400's last year was 1982. Then Ford brought the 460 back to replace it in heavy duty applications.
I don't recommend either the 351M or 400M. Not that they are bad motors, they are just VERY hard to find parts for.

Brad Godkin
1986 F350 CC/SRW
6.9liter/C6
THE SHORT ANSWER: I think that due to emissions concerns, years like '77?, '78 and '79 may get worse mileage than earlier or later years, but I don't know that for a fact. Ride, handling and comfortwise, I prefer my '88 to any of the earlier years, but I can't really compare it to any of the later years. I'm kind of down on the late '70's, but that's partly aesthetics, and due to the fuel mileage of the '79 302 we had. I believe serious strides were made in handling, quiet, (wind, drivetrain and road noise) and ride quality in the ’86 and up years. I personally think engine choice and chassis weight are more important than year, depending upon where you fall on the comfort scale. If comfort is important, later is better, IMO.
I base this on knowing the following trucks: Unless otherwise noted, all these trucks have the 300 c.i. six, a.k.a. the 4.9. I have a '72 (240c.i. six, restored), '81 and '88 currently, and we had a '64, '73, '79, '86 and '93 F-350 Diesel Dually in the family business, (all the company trucks were bought new) so I've had experience w/ every generation, lately, except the newbies. My '88 is the quietest of my "personal fleet," by far, and the best riding, noticeably so. The '88 also handles the best, but it's also the only one w/ front and rear swaybars, too. The '72 rides like an F-250, i.e., BAD, but it's only a little F-100 Stepside, w/ a 240 'Lil Big Six.
Forget years for a moment, let's talk about engines, as I feel this should be a bigger concern:
At the risk of offending the folks w/ 302's out there, Nate summed up my feelings as to why the 300 six is better, IMHO, than the 302. I would only add that I believe that because the six (and I'm serious here) doesn't have to work as hard as the 302, given it's slightly better torque, (a "good" Ford salesman told me this--maybe it depends upon which year you look at?) lower operating RPM (and more massive construction?) that it will normally outlast the 302 as well. Now I'm sure some years of 302 are better than others, and the V-8 guys can tell you which those might be, but I don't believe there's a bad "big six" year. As I say, I have three of them currently, if you count the 240 c.i. in my '72.
My buddy now has an '88 F-250 4x4 w/ 351c.i./5-speed ZF. Strong truck, all around. And he (somehow) claims to get 15-17 mpg!
I had not heard about 80's having weak frames, and my buddy had an '80 F-150 4x4, w/ 302 auto, however, a trailer hitch did bust off the back of it, so maybe it's frame was weak? It had been used hard, so it burned oil, got terrible (sub 10mpg) mileage, had poor power, and developed a knock, but this is only one admittedly abused truck. This was the truck he periodically had to jack the engine up in to clear sludge from the oil pickup screen, to fight a losing battle against low oil pressure. It did hang together long after we thought it would “grenade,” and towed my boat for years, (2 drags per year) but it was painful to watch.... This truck is one reason I’m not in favor of 302’s, which I admit is somewhat unfair, as the truck was not in great condition to begin with. But I believe a big six in the same truck would have told a different story….
Speaking of weak frames, my '81 needed new rear spring mounts, i.e., the "ears" that are riveted to the frame and locate the spring shackles. This truck was rustproofed, (drilled and filled) and has very little rust, just the square rear fender wells, as mentioned by ?, above, and front fender lips. But these rear pieces rotted away, while the forward (rear) spring hangers are fine. Go figure....
My '81 300 has had what sounds like a wrist pin knock, for the last 20,000 miles, but it never gets worse. There is (most likely) 190,000 miles on it (shows 90,000) and yet it uses only say 1-1.5 qts. oil/3,000 miles and gets 16 - 17 mpg consistently. IOW, can't kill it. BTW, the 81's compression is all w/in less than 10% of each other, and they're in the 180 - 190+ psi. Think it's just carbon buildup?
Bad years? My dad bought a brand new '79 F-100 8' 4x2 302 automatic in 1979, and it got 9mpg from day one. It may have come home "on the hook" a couple times too, but I can't remember.... It did ride a lot better than my ’72, but it was an 8’ box, which helps the ride vs. a stepside.
On the other hand, his previous truck was a new '73 F-250 H.D. 8' 4spd, with the 300 six, and this truck literally hauled things like bulldozer tracks off a D-5 (headlights pointed at the trees, with overload springs, 10-ply tires overheating so he had to keep stopping to cool ’em down) and everything else, for his construction co., then a friend drove it for like, at total of 15 years and multiple hundred thousand miles, and it was still a solid truck mechanically, albeit rusty.
While it seems to make sense to avoid the early years of EFI, I don't think you have to, actually, as the next company truck my dad bought was a new '86 F-150 4x4 8' w/ 300 six and 4 (or 5?) speed. Wasn't '86 the first EFI year? There were no EFI issues, or any other issues, that I can recall, other than maybe a front hub. The company trucks were all kept for 5 - 7 years, on average.
Charlez mentioned that the late 70's may have had thicker sheet metal and it wouldn't surprise me. While my undercoated '81 is unusually solid, my buddy's '80 was shot, the box was toast years ago, etc.... My '72 is very definitely thicker metal than '80+ trucks, as I have done collision work on it and know it for a fact.
The six has decent acceleration as well, and unless someone is doing some major towing, the six is the choice, IMO, at least in half ton, and maybe in a 3/4. My '88 has 140,000 hard miles (landscaper towed w/ it previously) but it uses minimal oil, is quiet, has great accel. and gets 15-16+ mpg. The '88 whizzed my boat along at an honest 75mph (I just had to see what it could do, then I backed off) and it had a little more steam left. As far as top speed, it’s easy to bury the speedo (calibrated only to 85 mph) but w/ the 3.55 rear, it’s still accelerating decently at that point.
Big Sixes Forever....
Dan
Ford Trucks for Ford Truck Enthusiasts
Also have 81 F250. Runs well but the frame is completely rotted thru over the rear axle-I had to fishplate steel over the gap. It has 105K and is a yard truck only.
Also have a 85 F250 that had a 302 EFI. The 302 coiuldn't get out of its own way and the EFI left me on the side of the road more times than I care to remember. This vehicle now has a 300-6 that is carbed. The frame rails are OK but the shock mounts all fell off a couple of years ago and the x-members are getting pretty thin. It has 140K. I'd never even consider an 85-86 EFI Ford ever again.
I'll take 73-79 F series w/ 300-6 over any other any day.
Even though I am a big advocate of 302's, you are correct about the 300 being very simple, reliable and built well. It has excellent torque at a low rpm, and fair mileage. This is what makes it a good truck motor.
As far as comparing it to a 302, reliablity is all in how the engine was taken care of. I personally have seen several 300's with over 300k. Stick ticking away. Using little or no oil. I've seen several 302's with well over 200k with no major problems. The I6 has seven main bearings, a very big PLUS and 40% less parts than any v8.
I don't believe that the 300 will get better mileage than a 302, and practically any 302 will out run a 300, but that doesn't really concern most truck buyers.
I've driven several carbed 300's and these trucks are considerably faster than the EFI 300's.
About EFI, I've never heard of too many problems with the first few years. Neighbor has an '86 302 EFI (BADLY abused), still runs great (not sure about the mileage). Another thing to consider is the last couple years of carbs were electronically controlled and had mazes of vacuum lines. These can be hard to get running just right from my experience. After fixing numerous vacuum leaks, etc. I think I finally have mine running right.
I would take the I6 over the 302 any day, especilly in a truck that works. I've towed over 5000 lb. at 65 with more left, and have no trouble getting past 85mph unloaded. I know of quite a few of these motors with over 200K on them still going strong.
Pastmaster, I'm curious, I thought EFI on the 300 added quite a few horses and made them even better. I don't consider my truck slow, but the newer sixes I've driven have felt faster.
1986 F-150 4x4 300 I6 NP435
1979 F150 Custom: 75 351W, Edelbrock & Holley
1987 F150 XLT Lariat: 88 351W EFI
Chevy 454: waiting for a truck (Mazda?Nissan?)
I hear ya, and although they’re not my preference, there’s gotta be some years of 302’s that are good, as they’ve sure got a loyal following, have more performance parts available, etc.... And you said a mouthful re: the importance of how an engine is cared for—to which I would add only that I believe how an engine is driven is very important as well.
On this point, I don’t know if you’re a boater, but did you ever notice how many fairly late model V-8 powered boats have been “recently repowered?” I notice, b/c my 165 hp. (2-barrel) Mercruiser I/O is powered by it’s original 1972 inline 6—a 250 c.i. C***y—yes, I admit it, but this engine is extremely reliable, and still strong (and actually fairly "high performance," based on specific output, in its own right). So here my boat engine is 29 years old, never been opened, to my knowledge, and the only thing wrong is a slight lifter knock at idle. I think V-8 boats are more likely to get the crap beat out of them b/c they’re considered “performance” boats, and so they die young. So it wouldn’t surprise me if 302’s get railed on harder than big sixes, by people that don’t know any better. Make no mistake, I run my sixes hard and fast every day, and for 12 hr. round trips on the weekends, but I maintain them and I don’t beat them unnecessarily, i.e., I don’t downshift for braking, normally, as brakes are much cheaper than driveline components, etc…. So maybe b/c V-8’s are raced more often than sixes, or b/c they sound better, people beat on them more? Just a theory—I still think the 4.9’s are inherently more durable than the 302’s, even if they're not as fast, but happily, Henry gave us our choice, right?
Certainly, seven main bearings is an advantage, as you note. Hey, maybe all that extra internal friction (from 7 mains) is one reason the mpg isn't better?.
One point you make surprises me. You indicated that you believe carbed 4.9’s are faster than injected 4.9’s. I have both, but I can’t tell why my EFI 4.9 is faster b/c it’s geared lower than the carbed 4.9, so I’d expect it to be snappier, and it is. My question is this: while I don’t have the hp/torque figures, somebody on this website stated that carbed 4.9’s had about 120 hp., and EFI’d 4.9’s had 145 or 150 hp. So if that’s true, I would think you’d feel the EFI’s were faster, unless perhaps your carbed engines are modified? Just wonderin’. It's all good.
). Just to rile my Dad he said that his truck would pull it no problem. If memory serves correct the boat and trailer weighed just about 10,000 lbs. I followed them over in my truck and we hooked up the F150. I couldn't believe it! that 300 pulled that boat better than my Dads chebbie with a small block ever thought of. lol. My dad still won't admit that that little truck did great. I was following them and saw it pull some pretty good hills without ever dropping below 40 MPH. the 300 is a torque monster. I think the numbers do not do it credit. I still love the sound and punch of a V8 under my foot but I definatly have respect for the 300. I still mourn it's passing. the 4.2 liter that Ford replaced it with isn't 1/4 of the motor that the 300 was. just my 2 cents. Take care everyone.Brad Godkin
1986 F350 CC/SRW
6.9liter/C6








