I'm pretty sure the 460s are flat tappets.

As far as boosting, especially a 460, I just don't need more power. When I got this truck I carried a light-weight slide-in camper and towed my '71 Bronco with my wife and 2 sons in the truck. So I needed a 3/4 ton crew cab. But the '95 F-150 SuperCab with 351, E4OD, 3.55 gears and 33" tires had enough power for me to haul that camper while towing a slightly lighter CJ5. So for starters, my power needs aren't that great.

And even beyond that, now I have a class C motorhome so I don't need to carry a camper, and I rarely tow the Bronco with the truck anymore either. So I really don't need a 3/4 ton truck. But I do still need a crew cab. Although my kids are now out on their own, I'm likely not too far away from having grandkids. And I don't want my truck to limit me too much in who can ride with me. Since I don't like any trucks newer than my '97, needing a crew cab keeps me in a 3/4 - 1 ton. But I really can get away with a 1/2 ton engine in it. And for the few times I do need to move a bigger trailer... well that's what the lower gears in a manual transmission are for. I'll be starting in 1st and I might not be hitting 5th too often.

The Godzilla 7.3L is certainly a fun option to think about. And as it gets a year or two under it's belt it might turn out to be a good option. It's certainly a good one to throw in the mix now. But I'm more interested in mileage than power. Maybe it'll be good at both (and likely better than a 460!). But I'm thinking the built 351 would be a better choice for me than the Godzilla. So the bigger question is if something else (like an LS) would be a better choice than the built 351.

 

If you want better MPG then you do need some more power. Not for the power itself but for the increased volumetric efficiency of the engine. Specifically more cubes, airflow through the heads/intake, and a truck/torque optimized cam.

 

Yeah, I get that ENGINE efficiency gives you both better power and better VEHICLE efficiency (assuming you don't use too much of the power). Better heads and optimized cam are definitely needed (and are a big part of why the newer engines are better out of the box than older ones). But I don't agree that more cubic inches usually improves vehicle efficiency. It doesn't always HURT as much as some people say. And a bigger engine can get better mileage than an overloaded smaller engine. But for a 460 to get better mileage than a 351 (for instance), the load has to be awfully big. Towing a travel trailer in the mountains? The 460 might beat a 351. But for normal driving with maybe a cab-full of passengers you don't need 460 cubic inches.

Similarly with forced induction. Yes it gives more power, but I don't see it as the best way to get better mileage. In a low-compression engine modest boost might improve mileage. But I think high compression would be a better way to gain engine efficiency, and then adding boost wouldn't be as beneficial.

 

Higher compression will certainly yield better MPG than boost for multiple reasons. By more cubes I meant a stroker small block as opposed to a stock displacement version. Comparing two different engine families (like a 351w and a 460) opens up too many additional variables to compare directly as a proof of concept for whether more cubes is better for MPG or not.

 

Okay, I see your needs more clearly now. I was under the assumption you still needed the truck for truck type stuff(besides seating for 6). Yes, you don't need a 460 for that. But the point is, that 460 will lumber along with tons of torque at low rpm, thus using less gas. Thus getting the rear geared down for cruising would be beneficial. Agree also you don't need forced induction. Again, that was me thinking you are still wanting to move a lot of weight more easily, with less gearing(using boost to improve the power).

I could see a stroker windsor, with good heads, good torque roller cam with mild compression doing a better job then the old 460.

 

I'm not saying I'll never use the truck for truck stuff. But it won't tend to much more than (rarely) towing a 32' travel trailer. And like I said above, I'll be happy with using lower trans gears and being a little patient when it is loaded like that. Heck, I was happy with the F-150 carrying the camper and towing the CJ5 with a stock 351, E4OD, 3.55 gears and 33" tires.

And yes, the 4.10 gears have got to go! That is, unless I add a Gear Vendors to try to get the best of both worlds (which is an option). But whatever engine I go with is going to need to be happy pushing at least the empty truck around with 3.55 (or taller) gears. Trucks with lower gears than that are just to busy / buzzy for my taste. I know the 460 could, but it would still be (very) low teens at best. Yes, in terms of bang for the buck that's undoubtedly my best option. But like I said earlier, I'm not looking for the best bang for the buck, I'm looking to get near 20 mpg without spending a fortune.

So it's looking like a built 351 might be my best bet, with an LS still an outside possibility, and a Godzilla being a really cool possibility.

If I go with the 351 it would likely need to be a stroker with aluminum heads, and a cam (and preferably a roller cam I would think). But sticking with normally aspirated.

The LS has better heads to start with, and I probably wouldn't build it. The question is whether it would have enough low end torque to make me happy (doesn't need to be a ton, but has to be able to stay in OD a lot more than my 5.4L and 6.8L Tritons).

And the Godzilla is too new to have many answers. What kind of mileage will it get? What transmissions will bolt on? What will it take to get it wired into an older truck? How expensive will they be? I can't imagine a Godzilla swap ever being as mainstream as an LS swap. But it certainly has enough to offer that it'll be fun to see what happens with it!

In the mean time, I have a year or two more projects on my Bronco before I can actually start wrenching on the truck. So I'll keep thinking about stuff. And if anyone wants to add more thoughts in here, I'll be happy to hear them!

 

If you need low end torque improve what you have,I was not impressed with the low end torque on that GMC I used to tow a car with. I am guessing I was towing about 6000 pounds and it drank gas like a big block and no power and I thought I was going to kill it.

 

Rebuild your 460 into a rollerized 429 with 9.5ish compression and cam made for low to mid range. Headers and intake with reduced pumping losses in mind. OEM or aftermarket EFI that will control your E4OD.

Serving suggestion.

 

I'm really not interested in improving the 460. I know I could get a lot more power out of it, but I don't need that. I know I could get also better mileage from it than what it currently does, but probably not better than low teens, and that doesn't meet my goals. And I know I could get those low teens at a low enough cost that I could afford to put more gas in it. But affording enough gas isn't the goal. A truck that can get near 20 mpg is the goal. And I am pretty confident that a 460 isn't a path to that goal.

 

a USED LS is the logical step where cost is involved. If your talking rebuilding one, then you will be in it DEEP.. They win because a $200 engine with 200k miles can still make good power... A 6.0L with a couple small turbo's on it will haul the mail and achieve decent MPG while doing it.

 

A few simple aero mods on the truck will likely make as large of an impact as engine changes. Namely a large air deflector under the front bumper to keep air from going under the truck, as well as aero cap on the bed to smooth out airflow over the cab. If you have large towing mirrors, making those temporary and running smaller mirrors the rest of the time would help as well.

http://csus-dspace.calstate.edu/bits...d-finished.pdf

https://ecomodder.com/blog/aerocaps-for-pick-up-trucks/

 

Regear to 3.31 (new 60/10.5 have them and will fit the 60/10.25)

 

Just some food for thought... My stock 91 f250 has a 351w and the zf 5 speed and 3.55 gears, I get about 13-15mpg mixed... And I beat the **** out of it. I also have 33" tall tires. I'd be willing to bet you'd hit 17-18mpgs with a roller 351w, some gt40 heads, weather aluminum or cast iron, and a street cam. Also, not to sound like an advertisement, but Edelbrock's Pro Flo-4 system could benefit you with a 351 because it uses sequential port fuel injection instead of Joint Batch fire our trucks use. Another plus that kit gives you is the ability to use stock cruise, have a pre uploaded tune for Milage or performance. I'm going to be going with that kit soon so I'll let you know how it all goes!

 

if he dont get a manual, would it control the E4OD?

 

When I was on the phone with edelbrock yesterday, the rep told me there is a CAN connection in the wiring harness for transmission input/output. But I am not sure what controller is needed or anything like that. That would be another question for Edelbrock. If he ends up going with an older, non electronically controlled transmission all he would need is a kick down cable coming from the throttle linkage. Although I definitely think a manual with overdrive is the best choice for his application.