Time for a vote! My current truck is near completion and I love having projects, so I'm starting to get the gears turning for a new engine build. Not sure if I'll end up putting it into a 2wd street truck or a classic wagon/sedan for the family. My ultimate goal is to make it my daily driver, which entails 30 miles each way on the interstate. I want good mileage and reliability, with reasonable power as a bonus. It is either going to be carbureted or have a stand-alone EFI system (FiTech or similar). Must be a manual trans. This will be a complete, frame off build with new wiring, new suspension, etc. Based on these criteria, I'm thinking a turbocharged 300 with EFI would be a cool, somewhat challenging project that would fit in just about any engine compartment. There are other engines with better aftermarket support though. Would I get best mileage/reliability/driveability out of:


1) Turbo 300
2) stock 300
3) SBF
4) BBF
5) Other?


I'd like mileage to be somewhere in the mid 20s or higher....help me get there with something cool!

 

If diesel isn't out of the question, why not a 4BT Cummins? They make enough power to work with, especially if it's a single cab pickup, and you'll get pretty good mileage.

You won't see mid-20s with a BBF; I can't speak for the I6 or the SBFs.

 

I knew the BBF wouldn't get me there, just wanted to see who was paying attention.


My 460 is rocking single digits most days. I have looked at the 4bt - how do you think it would behave in a classic car? Something like a falcon wagon is not out of the question at this point either. Would weight be an issue? All I know is I want something pre-computer BS. No coyotes for this build!

 

It depends on your ability to beef up the suspension; the 4BT is still super heavy.

Factor in overall height and you may be having some issues fitting it into a lower-profile vehicle like a wagon.

If you're not stuck on domestic motors, look into the Mercedes OM617. 5cyl diesel, available in turbo configurations, and adapting a manual box shouldn't be too hard. The naturally aspirated 617s came with either a 4-speed or 5-speed manual too, but good luck finding that here in the states! With some fabrication, you could probably work in a T-5 or something along those lines. They'll return pretty good mileage, and are fairly easy to maintain; parts are still plentiful and being produced too. However, there isn't much "aftermarket" support out there, so any builds for power will be your own R&D.

That said, there are plenty of threads out there on many Benz forums of owners building up their 617s for a bit more power without sacrificing much on economy.

Here's one swapped into a Toyota pickup. Super clean swap:

 

I have to add, it seems people who are swapping the 617 into Jeeps and Toyatas appear to be making all sorts of transmissions work!

 

4bt all the way. Mileage master, especially in these old light trucks.

 

Thanks for the input guys! I'm pretty much set on either an older Ford or 4BT. I like the fact that parts are cheap and easy to get.


What kind of mileage could I expect out of a SBF?

 

Realistically? Probably mid to high teens, depending on the weight of what you're putting it in.

 

I get around 16-17 hiway with my 96. It's a 4x4 5.0 with a 5 speed and I think 3.55:1 gears (haven't had to take that apart yet). It took some intake, exhaust and timing mods to get to that mpg and I have to baby it to maintain it. I can't imagine getting 20 mpg consistently with a sbf. but I'm sure someone will claim that they do. I have also owned 2 300-6cyl trucks and they got worse mileage than the 5.0 (had to run them a little harder). A turbo inline 6 would be really cool but once again I can't see it getting good mileage. A turbo 5.0 though.....

 

I get 13 out of my high compression 351 build (built for torque) with heavy hummer wheels and tires. I'd be curious to see what it'd get with a lighter setup.

In a small truck, high teens would be achievable with the right build, and 93 octane. I happily run 93 since I get 13-14 in what should get 10.

Expect an easy 25 mpg with a healthy 4bt, a light truck could easily get 30+ if setup properly.

 

On another forum I'm on that's strictly for tuning carburetors, there is a guy running a 70 Chevy wagon getting 20s for mileage. I don't see why the same couldn't be done for a Ford wagon.
​​​​​​​If I remember right it's a 421 small block stroker and a moderate camshaft and a quadrajet. So why couldn't a stroker Windsor do the same. Get the quench set right and gear it accordingly and even at 10:1 you could get by on pump gas. I'll see if I can find his thread and get more info on his combo. Because in reality an engine is just an air pump right

 

If I were to do another swap, I would use either the 4BT or an OM 617 Mercedes. The OM is lighter by a bunch but the 4BT makes big block torque. There are adapter plates for the OM to just about anything common these days.

Just my $0.02 USD worth.

 

My EFI 300-E4OD-3.08 geared 2wd truck gets 16-22 mpg, mostly highway. Manual transmission should help, and if you can get it to fit in a car, better aerodynamics might get a person to 25 mpg or better. I think Galaxies with the 240 and 3 in the tree could get 25 mpg back then. Keeping the RPMs and aerodynamic drag low seems to be the way to mpg with the 6.

A 302 will fit in a lot more places, and has much better support, though. Roller cam availability at a reasonable price is also a good thing. I used to get 18-20 highway mpg with EFI 302-AOD in Crown Vics.

 

Ranger with a turbo four...

 

Another vote for a 4bt

Can pretty easily be made to make 200hp/400tq
get 25+mpg
and still be daily drivable
But I would NOT call the parts cheap.
My base USED 4bt was $2,200


That is EXACTLY why I am putting one in my ranger(daily driver)
4bt with VE pump
zf5(small block)
4406 t-case
4.10s
285s