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81 F150 Tach Install

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Raywilson

Re: 81 F150 Tach Install

I've got a 302 AT and don't push it very hard, best I've done is 11mpg. Full size Ranger. 2- 20gal tanks

1981 F150 XLT Ranger Trailer Special
302 automatic

Gary Lewis

Re: 81 F150 Tach Install

Administrator

Raywilson wrote

I've got a 302 AT and don't push it very hard, best I've done is 11mpg. Full size Ranger. 2- 20gal tanks

Yikes! I can get that consistently with Big Blue at 65 MPH on cruise, and can get 12 feeding it manually. I think you may have a bit of MPG left on the table.

Gary, AKA "Gary fellow": Profile

Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI

Raywilson

Re: 81 F150 Tach Install

I've only had it around town, never a road trip. Not yet anyway. Has the AOD transmission, so hiway might/should be better.

1981 F150 XLT Ranger Trailer Special
302 automatic

ArdWrknTrk

Re: 81 F150 Tach Install

Administrator

In reply to this post by mat in tn

Oh, how I wish that was true for me!

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

Gary Lewis

Re: 81 F150 Tach Install

Administrator

Ray - I don't measure it around town, but I'm sure it would be far worse than 11.

Jim - I'm a grandpa and drive like one.

Gary, AKA "Gary fellow": Profile

ArdWrknTrk

Re: 81 F150 Tach Install

Administrator

And , I'm a lunatic.

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

mat in tn

Re: 81 F150 Tach Install

In reply to this post by Gary Lewis

I'm also a grandpa and I too drive like one. however, I don't think all grandpas drive the same

my 81-camper special with the 351m gets better than you are getting. not much mind you. but I'm getting 15 easily around town and 19 is achievable over the road from my 93 flare side. not the same I know but volume times rpm is. I feel you are not tuned to full potential.

Raywilson

Re: 81 F150 Tach Install

Grandpa's all around! I'm 73. Everything seems to running fine, starts instantly. No fumes. I have a friend who has a 70s Sun Tune-up "computer". He's a carb specialist as well. Goes by Henry the Carb Guy. I'll give him a call...
Ray

1981 F150 XLT Ranger Trailer Special
302 automatic

mat in tn

Re: 81 F150 Tach Install

being a trailer special I'm guessing it has the c6 and probably a 3.00 gear. not the best for either around town or highway but a fair compromise nonetheless. there is a real reason for the advent of the overdrive in f150 trucks however I expect you should be able to get 13-14 if tuned right.

Raywilson

Re: 81 F150 Tach Install

It has automatic overdrive transmission. Maybe the vin will tell me the rear gear ratio

1981 F150 XLT Ranger Trailer Special
302 automatic

Raywilson

Re: 81 F150 Tach Install

3.25 ratio- hwy gearing. That explains my poor intown mileage

1981 F150 XLT Ranger Trailer Special
302 automatic

mat in tn

Re: 81 F150 Tach Install

3.25 with an od? I'm guessing it's an aod (metric) with the early kick down rod for tv control. I don't know much about another option. the majority of the aod's were paired with the 3.55 gear in 8.8 or 3.50 in 9". I'm running 3.73 in my flare side and it's my best mpg truck. l am very interested in other combinations as I am always trying something new. I am building one with a 5.0 carb and an aod with a 3.31 currently. this is fairly close in final drive ratio to yours.

Raywilson

Re: 81 F150 Tach Install

This post was updated on .

Yes, AOD. On Gary's rear axle chart, my VIN shows I have a 15 axle ratio or a 3.25 ratio. Not great milage about town.

1981 F150 XLT Ranger Trailer Special
302 automatic

mat in tn

Re: 81 F150 Tach Install

oddly enough its possibly not good on the highway either as you likely are turning too slow for efficiency and in 1981 I don't think the 302 had more than 145 hp. and hp is not achieved at low speeds. it is counterintuitive yet when the engine is allowed to spin a little faster and easier yet a bit lean, the mpg can go up. with an aod ,the od is the deepest in these trucks at .67 meaning your final drive is 2.18. 2.5 seems to be the sweet spot from my experience. it would take a 3.73 to achieve this in your truck. if you were looking to have a bit more feel of power you could go with 4.10 but that will possibly go past peak mpg and start drinking again. but tow a trailer it will do!
in 1981 the national speed limit off 55 was still in effect and ford was engineering. these to be practically coasting I believe. now with everything including econo box cars going 80 on the interstate you are going to need to stay on the throttle a little bit and keep power being made, but I'm rarely on the throttle as much as 1/8". some trucks I just "feel" the pedal.

Raywilson

Re: 81 F150 Tach Install

In reply to this post by Gary Lewis

Pics of my new and old dash replacements. My old one has a white cable going to the steering column. New one does not and doesn't have way to connect. What should I do?

1981 F150 XLT Ranger Trailer Special
302 automatic

Raywilson

Re: 81 F150 Tach Install

This post was updated on .

Thank you for the information, that's really helpful. I'll look for a 373 ratio you recommended. I see the 373 is a 1986 part. Is it physically interchangeable w my 81?
Ray

1981 F150 XLT Ranger Trailer Special
302 automatic

Gary Lewis

Re: 81 F150 Tach Install

Administrator

In reply to this post by Raywilson

The part the white cable goes to is held on with a couple of screws. So you can move it to the new instrument panel.

Gary, AKA "Gary fellow": Profile

BigBrother-84

Re: 81 F150 Tach Install

Yep, this part can be transferred from a cluster to another.

Be careful. I don’t have a three on tree, but I heard this cable could be somehow fragile.

Am I right, guys?

Jeff / 1984 F350 Crew Cab 4x4/5.8L w351 4V/ T18/ D50 4.10 front/ 8' bed.
Restored 2019-2022.
Nicknamed «Big Brother 1984», due to its soooo-looong shape & nod to George Orwell's 1984 famous novel.

Gary Lewis

Re: 81 F150 Tach Install

Administrator

That cable is for an automatic transmission's gear display. And yes, it is very fragile.

Gary, AKA "Gary fellow": Profile

Raywilson

Re: 81 F150 Tach Install

Thanks for the description of what it's for. Hope it'll reconnect to the new one

1981 F150 XLT Ranger Trailer Special
302 automatic

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