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Discussion Starter · #1 ·
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?
 

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Discussion Starter · #3 ·
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.
 

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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
 

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Build it right the first time
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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.
 

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Hates: Liver. Loves: Diesel
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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.
 

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Discussion Starter · #9 ·
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. =]
 
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