vin DSO numbers

  well, I sent for the Marti Report, I guess it will be a little bit.
In the meantime, would anyone know if there is an overdrive system
that can be added on to the driveline, I would like to keep it as stock as possible.
but the 4-speed granny with a HO 302 mustang engine drinks gas bad.
I know I can change gear ratio or change the tranny.
I saw a truck on Marketplace with a manual with a red knob on the shifter.
I Questioned what the knob was for. he replied it's (DUAL). I questioned again
dual what, rear-end / transmission??  no reply yet from him!
 Clayton
 

old yeller wrote

I saw a truck on Marketplace with a manual with a red knob on the shifter.
I Questioned what the knob was for. he replied it's (DUAL). I questioned again
dual what, rear-end / transmission??  no reply yet from him!
 Clayton

That was likely a "GVOD", or Gear Vendors Overdrive: https://www.gearvendors.com/index.html

I have done a couple 5spd swaps. They're relatively easy and inexpensive (usually) if you can find one.

what's the point of trying to keep it original if it already has a mustang engine? one simple thing to do might be a differential gear change. that would keep the original format at least.

You are right. but that is the way it was when bought.
 just looked up GEAR VENDORS, I had no idea of the price of the units.
It may be different gears or tranny. I don't mind the granny; I usually start in 2nd.
 Any suggestions on a 5 or 6 speed that would be an easy swap?
Thanks for the input.

yes, gear vendors are expensive. that is one reason for five speed upgrades. we all want the best range of performance and economy, but these are not high mpg vehicles. everything comes at the cost of something else. start by asking a few base questions. (1) what do I have vs what do I want? (2) how many dollars will I spend to save dimes?
 you have a four speed, is fourth an overdrive? what mpg are you actually getting? if you are driving it as a three speed are you driving it easy of winding it out like I would? I'm still a kid at heart.

I went back and read your info about the truck. there is a lot there that does not scream mpg. 3.50 gearing for one. if you change one axle you change them both. that can get expensive especially if you don't get them right. the transmission change is probably the best compromise that you will get. even then you need one compatible with your transfer case and most likely will be converting from a mechanical clutch to a hydraulic meaning a couple more changes and a little metal work. hopefully another here will have more of the details involved like shifter locations etc.

Up till about 2 years ago you could get Advance Adapter Range Spliter over drive that was way cheaper than the GVOD and could be used in 4x4 unlike the GVOD. Think I got one of the last they made and I had to wait for it.

As Matt said you have to step back and look at what you will be using the truck for and want in the end for the money put out.
You already know the price of the GVOD and add a little more for other things that pop up.

Look into front & rear axle gear set. Can you do the gear swap or needs to be farmed out? Gear swap is not easy and you now have 2 to do. So if a shop has to do it add more $$$$.
Also with a gear set change it will be harder on the clutch as you will need to slip it more to get rolling from a stop. You could use granny but try than now and see how you like doing that every time from a stop!

That leaves a 5sp transmission swap. Guys that have done this love it and it shifts better than the "truck 4sp" you have now.
Thing is you no longer have a granny first gear to get heavy loads moving from a stop.
I dont know if the 5sp first gear ratio is lower than the 2nd gear of the trans you have now or not but if lower would help with heavy loads and the 3.55 gearing you have now.
I also hear the 3.55 and the over drive of the 5sp work out pretty good on the high way.

If doing a 5sp swap it is best to get a full parts truck and park it next to yours for the swap as there are a lot of little things that need to be changed and going to the JY could be a PITA.

After reading posts of the ZF5 transmission needing rebuilt most of the time when used and all the parts I would need to do the swap in my 81 F100 and not finding full parts trucks by me or having the time to hit junk yards it looked be about the same $$ as the GVOD.
Only thing is I could keep my granny first gear transmission if I went GVOD.
I also did not like that with the GVOD you could not split every gear and had to be going (think?) 30 MPH before it would kick in the OD. So starting in granny and then splitting was out of the question as you are3 under the 30 MPH limit.

My 81 F100 flare side with a 300 six is my back up to pull my 20ft open deck car trailer and with car could be 6000lb so need the granny gear for starting and that is needed with a 2.75 rear gear.
Most of the time the truck is used for weekly trash runs, to / from work (40 miles each way) and shows on weekends.
I do have Advance Adapter over drive so I can split all gears turning my 4sp into a 8sp transmission.
Some of the ratios are a little to close together to split when not loaded but if in slow traffic and in between gears that dont work I can split it.

I do like that the RPM is lower so less wear on the motor but so far I have not seen the MPG go up but I am still adjusting timing and then carb.

Sorry so long but wanted to post what I went through when looking to add over drive to my truck and the options I had at the time. I think if mine was just a driver the M5ODR2 would be the way to go if I could find a parts truck.
Dave ----

Use the calculator at Documentation/Driveline/Calculators to see gear ratios, do what-ifs, etc.  It is loaded with the gear ratios for most of the transmissions you might be interested in, and there's an Other column where you can add another tranny if you want to compare.  And there's a place to put in an overdrive unit's gear ratio.

Looking at the cert label I see an F for the tranny, so that's a T18 which has a 3.09:1 2nd gear and the M5OD has a 3.90 1st gear.  So starting from a stop would be easy with the M5OD - unless you are pulling a heavy trailer, and then that may take some clutch slipping.  (Or, do as Jonathan does and start in 4Lo, but that's not for the faint-of-heart.)

Anyway, you can use the calculator to see what speed you'd be running in any gear with any transmission, axle ratio, or tire size.

I knew you had that cal as I used it a lot when I was looking how I wanted to go with over drive and final drive ratios.

And I am sure I even checked it out when a was looking to replace my T18 for a NP435 I have now what the ratio different might be.

The M5OD with a 3.90 first and his 3.55 rear gear he would have a 13.845 total for a first gear where he has a 10.9695 with the T18 2nd gear of 3.09 and the 3.55 rear gear.

So if he thinks he has to slip the clutch to much now then the 13.8xx would be real easy on the clutch from a stop. If he found with the 13.8xx was to low he could run a taller tire and not hurt starting from a stop and lower the RPM's more.

I just think Ford put too tall gear ratios in the trucks to meet the MPG number and it dose not help when you have to start from a stop or move heavy loads. Just look at the 2.75 rear gear my truck has  I do like the granny gear + over drive (split) to start moving with as it is easy on the clutch.
Dave ----

Yep, I knew you knew.  In fact, you helped design it.  But others might not know about it so I wanted to mention it.

As for the axle ratios, I've not been around many trucks with the 300 six.  But the V8 trucks I've been around mostly have 3.50/3.55 gears, and w/o an overdrive the engines are spinning pretty fast on the highway.

I guess because the 300 six has TQ off idle is why both of my trucks have 2.75 gears LOL
Dave  ----

Hi all! Got my Marti report, I had a few Questions for them. take a look. The door tag doesn't match. I asked about the tires and weight. Marti "We can't alter their data. We can just report what they have logged for the VIN." So, I asked Where did you get the info for the bottom left, Vehicle Equipment? Marti " That comes right from Ford's production record for the VIN." I replied back, Thanks for the info. , but it does not make since. this also calls out the 3.50 gears, unless they have been switched?

It is hard to read your report as the pic is so small.  Can you post the pic full size?

Also, your tag appears to show 3.50 gears, which matches the Marti report.

So, what differences are you seeing?

Yes, the tag on the trucks rear-end and the report show 3.50.
It was mentioned Big 6 mostly had 2.75
I have to admit this is a plain jane truck.
This looks better.

this seems to be a truck meant for dedicated service not general commuter. when you match the 4.9 with a manual non od trans and a 3.5 gearing you are expecting it to be used daily in a steady work environment. the fact that it's a plain jane supports this also.
we just finished a re-fit of an 89 f250, 5.8, c6, 4wd with 4.10 gearing. supposedly from an air force base and likely the only highway it ever saw was on the flat bed crossing the country.

That does look better.  And it does look like a Plain Jane truck.  As Matt said, bought for a purpose.

I was thinking farm truck. It's a brute with the 302 and granny. sorry for the delay in replies. Yall thew a lot at me, had a lot of research. Thanks

old yeller wrote

Yes, the tag on the trucks rear-end and the report show 3.50.
It was mentioned Big 6 mostly had 2.75

My 1980 F150 Flareside had the same drivetrain when it was new. 302, T-18 Warner 4spd, and 3.50 gears (with limited slip rear too). I have the Marti in PDF...not sure how to post it large like that? Edit:...sorry, mine came with a 302 and was swapped to a 300 inline 6. I thought this one was a 302 factory.

We can post pdf's on here by embedding them.  I do it all the time, so if you want send me the file and I'll post it.

How's your milage? As far as the Pics, all my pics were PDFs, I had to change them to JPG. I think I used: https://www.adobe.com/acrobat/online/pdf-to-jpg.html No download, just use it on the screen and save to your file. Do you or anyone have any idea about the dash covers on the web. Do they fit and look good?? Not the carpet, it looks like a plastic cover.