[65Stanger]

Well, I got my Mustang squared away, and running strong. I am also halfway through a '62 Ranchero. =D I got some new questions about a truck I've been trying to get running just right, but can't squeeze more than 10 mpg out of the thing. It's a 1986 F150 XLT Lariat with a 351W, 4 bbl carb, c6, 2.73 9" rear.

We've been trying to pull all the mileage out of it that we can, and I think I have a good plan on how to do it. We want to take it cross country in the next 3 months, so I would have to bust balls to get it done, but I think it could be done.

Has anyone swapped a T5 into an '80s F150? I think that would severely help with mileage. =D I'm going to do the most amazing tuneup I can do, try and stick a T5 in there, and see if the mileage hella goes up. It definitely should. =] We were also thinking about swapping to a 2 barrel intake, as this isn't a smoke 'em every time we hit the gas truck. We want a cruiser, that gets good mileage. We are buying an '83 f250 truck with a manual tranny, and I was thinking we could gut the pedals and clutch setup for the '86, and swap to a T5. What's a good 2bbl for a 351W? Thanks for the info.

Basically, here's everything in a nutshell:
2bbl intake/carb swap
T5 manual tranny
great tuneup

The mileage we're hoping for is high teens, 16-17. Possible?

[techinspector1]

Check the throttle bore sizes between the primaries of the four barrel and the two barrel. I'll bet the four barrel primaries are smaller. All you have to do is keep your foot out of the secondaries.

[65Stanger]

I thought the same thing, before I ever drove in the truck with him. He drives like a grandma. Almost never goes over the speed limit (maybe to pass someone, but never cruising), takes forever for him to get to the speed limit... When I drive the truck, I mob around in it, and pedal to the metal it. =D He's the one getting the consistently bad mileage though.

[RippinRon]

Lower gears might help getting a that truck moving more easily.

[65Stanger]

we have a 3 70 gearset for the 9". Was thinking about swapping.

[OneMoreTime]

With computer contolled injection I am getting 15-16 in an f150 4wd...you might get there with a carb but I dunno..best thing I ever did for mileage on a 4bbl was to set it up so it took a lot of throttle pressure before the secondaries opened..that and a good tuneup..check for vacuum leaks..and make sure you are getting the proper advance in the dist..

If it is a high miler you may be getting some blowby so do a leak down test and a compression test to ascertain engine condition..

If it is currently an automatic and a high miler the bands may be slipping just a bit..combined with the engine issues the tranny could be part of the issue..Just takes a bit here and a bit there and mileage goes in the dump..

Sam

[kuhn-77]

I personally am not a big fan of quadrajets but they do get great fuel economy, so If you buy a spreadbore dual plane manifold for the 351W and put a quadrajet on it and adjust the secondaries to come in late, plus your T5 tranny I see no reason you couldn't get 16 mpg out of it or even more. The small primaries in a quadrajet give it excelent fuel economy thats better than most 2 barrels ever thought about getting.

[curtis73]

Unless you want to castrate the truck to a very low GVW, steer clear of the T5. Its not a terrible choice, but why put a light-duty car transmission in a truck?

NV4500 is what you want. Good ratios for a truck, good torque capacity, and good GVW rating.

[65Stanger]

Sounds good. The motor is new. Good compression. Q-Jet, huh? =D I don't know how to adjust the primaries and secondaries. I'm used to my little 1 barrels on my sixers. =D Great economy there. Thanks for the info guys, I'll go out and do some more research, talk to my bud, see what we wanna do, and shoot back. =]