300 inline 6, 5 speed trans conversion
Thread Starter
|
Lead Driver
Joined: Sep 2003
Posts: 5,241
Likes: 3
From: Other side of the sunrise
300 inline 6, 5 speed trans conversion
A friend of mine asked me to post a question on FTE, of whether there is a 5 speed manual transmission that will easily swap into to his 1970 F250 4x4 with a 300 inline 6. If anyone has any information on this type of swap, please offer your knowledge. He says he wants to try and improve his fuel economy.
Thanks, T
Thanks, T
Hotshot
Joined: Oct 2002
Posts: 18,488
Likes: 22
From: The Big, Oregon
Not too easily, but an earlier ZF with an external slave might work. You may be able to convert that to work with the push rod linkage, otherwise you could add a hydraulic clutch to the truck's firewall.
Senior User
Joined: Sep 2009
Posts: 198
Likes: 3
From: Burbank, CA
I'd have to question if it would even be worth the trouble. If you got the 5-speed in there, what you'd be doing is lowering the engine rpm from, say, 3000 to 2400 rpm at highway speed. But you'd still be pushing the same big, heavy brick with the 4WD drivetrain drag, using the same long-stroke six cylinder. I doubt that the mileage would be significantly different carrying the same load at the lower rpm. It might even be worse.
Lead Driver
Joined: Mar 2008
Posts: 7,182
Likes: 381
From: Near Los Angeles
I'd have to question if it would even be worth the trouble. If you got the 5-speed in there, what you'd be doing is lowering the engine rpm from, say, 3000 to 2400 rpm at highway speed. But you'd still be pushing the same big, heavy brick with the 4WD drivetrain drag, using the same long-stroke six cylinder. I doubt that the mileage would be significantly different carrying the same load at the lower rpm. It might even be worse.
BTW, Ford did put the ZF behind the EFI 4.9 (300), and it is much sought after conversion.
Logistics Pro
Joined: Nov 2003
Posts: 4,371
Likes: 7
From: PA
how good is this T5 trans? ive heard they easily break with any beating of the truck because the truck weighs so much and the trans can't handle it. ill be looking for a 5 speed swap myself next year hopfully so any help will be great
Trending Topics
Cargo Master
Joined: Feb 2006
Posts: 3,009
Likes: 250
From: North Pole, Alaska
They are utterly worthless for a 4wd application as 1st is somewhere around 3.0:1. Depending on the engine chosen, look for a ZF, NV-4500, and at the least is the MR Mazda 5 spd found in F-150's. I think that there are kits to put NV-3500 (?model) trans in Broncos, so they could be used also, maybe. If you have an FE, I think you are stuck using the NV trans as they can be had with an adapter bell housing specially made for the FE.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
Lead Driver
Joined: Mar 2008
Posts: 7,182
Likes: 381
From: Near Los Angeles
4wd ZF's are a bit pricey--6--$800 range for a used one, and the 2wd's can be found for 2--$400. Ford put the ZF on F250's up.
Logistics Pro
Joined: Nov 2003
Posts: 4,371
Likes: 7
From: PA
What is the NV's and ZF's 4x4 5th gear ratio? And when did they start using these in fords and dodges? I'm guessing these are hydraulic clutches? What is all needed to put one of these trans in a 71 f250 4x4?
Senior User
Joined: Sep 2010
Posts: 129
Likes: 0
From: North Idaho
Pretty well doable, especially with the divorced t-case...My brother has a 77 highboy with a 300 6, We bout a 2wd zf5 speed for it. The plan was to take the old trans out, slide the new one in, mount up a slave cylinder for the clutch, shorten the intermediate drive shaft about 2 inches, or whatever it needs, and then fabricate a bracket to hold the t-case shift lever. and then add the turbo
Senior User
Joined: Sep 2010
Posts: 129
Likes: 0
From: North Idaho
also, you will want a small block zf5, 1st 5.72 2nd 2.94 3rd 1.61 4th 1 5th .76
with 4:10 gears and 31.5 inch tires 235 85 16 you will turn about 2200 rpm at 65 mph vs about 2900 rpm with a 4 speed
RPM / Speed / Gear Ratio Visual Calc
with 4:10 gears and 31.5 inch tires 235 85 16 you will turn about 2200 rpm at 65 mph vs about 2900 rpm with a 4 speed
RPM / Speed / Gear Ratio Visual Calc
Thread
Thread Starter
Forum
Replies
Last Post
BiltFordTuff
1973 - 1979 F-100 & Larger F-Series Trucks
11
Jan 4, 2020 09:24 PM
Michael Sizemore
1961 - 1966 F-100 & Larger F-Series Trucks
3
May 7, 2014 09:53 AM
300, classic, conversion, diesel, ford, inline, manual, speed, straight, strait, trans, transmission, transmissions, truck, v8
