Two speed diff?
Thread Starter
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Fleet Mechanic
Joined: Jun 2019
Posts: 1,898
Likes: 234
From: Southern California
There is an old saying, "you have to pay to play" If you want to compete with today's vehicles on the road, you need to invest in equipment used on todays vehicles. Namely an overdrive. Once you have the go power, then you need the whoa power to stop. You'll probably want disc brakes too.
Probably just end up tossing the 3.25-1 pumpkin I have in it and be happy.
How she looks currently
Tuned
Joined: Oct 2018
Posts: 368
Likes: 6
I run a '66 with a 240 and three speed, 3:50-1 rear, and she'll run all day at 80-85 (and I have run her 250 miles that way, freeway all the way).
No idea what she's tach-ing, though I finally found a 2" tach I'll need wire in.
Drums, with all new linings (not OEM, actualy New Stuff) will prove to be all she'll need, if my own experience with 60's Fords is any clue.
Though there are those who'll tell you you've a death wish and you're the vilest sort ever to put key in ignition...
Yup, I'd say that you're on the right track.
No idea what she's tach-ing, though I finally found a 2" tach I'll need wire in.
Drums, with all new linings (not OEM, actualy New Stuff) will prove to be all she'll need, if my own experience with 60's Fords is any clue.
Though there are those who'll tell you you've a death wish and you're the vilest sort ever to put key in ignition...
Yup, I'd say that you're on the right track.
Thread Starter
|
Fleet Mechanic
Joined: Jun 2019
Posts: 1,898
Likes: 234
From: Southern California
I run a '66 with a 240 and three speed, 3:50-1 rear, and she'll run all day at 80-85 (and I have run her 250 miles that way, freeway all the way).
No idea what she's tach-ing, though I finally found a 2" tach I'll need wire in.
Drums, with all new linings (not OEM, actualy New Stuff) will prove to be all she'll need, if my own experience with 60's Fords is any clue.
Though there are those who'll tell you you've a death wish and you're the vilest sort ever to put key in ignition...
Yup, I'd say that you're on the right track.
No idea what she's tach-ing, though I finally found a 2" tach I'll need wire in.
Drums, with all new linings (not OEM, actualy New Stuff) will prove to be all she'll need, if my own experience with 60's Fords is any clue.
Though there are those who'll tell you you've a death wish and you're the vilest sort ever to put key in ignition...
Yup, I'd say that you're on the right track.
Tuned
Joined: Jan 2007
Posts: 334
Likes: 100
From: Salkum
I went from 3.73 to 3.00 with the 3.03 trans and a 300 six. Paid $40 for the 3.00 diff off of FB. It was the best change I made. Wouldn’t want to pull my 19ft boat out of the water at a steep ramp but for everything else I do it work perfect.
Thread Starter
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Fleet Mechanic
Joined: Jun 2019
Posts: 1,898
Likes: 234
From: Southern California
Guess it's time to pull that pumpkin and count teeth, see what I really have for a spare, and the condition I suppose.
Tuned
Joined: Jul 2009
Posts: 472
Likes: 55
From: Nor Cal
FWIW here are some real MPG numbers with my Gear Vendors. I know my drivetrain is different than yours but again, FWIW.
My '65 300ci L6 stock not rebuilt 107K miles, T18 4 speed, 3.50:1 rear, with Gear Vendors.
On recent trip from Nor-Cal down the to Atascadero, lightly loaded, all highway going 65-70 mph, 17 MPG.
Don't know rpm, yet to install tach.
Never made that same trip pre-GV but would estimate it would have been 13ish MPG+-.
I get 12-13 MPG with the truck packed HEAVY pulling the '62 Shasta (2,500 lbs) in the 55-60 mph range going up I5 to Lake Shasta. Of course, as my Dad used to say, that's going North which is uphill going South is downhill so you get better MPG
Although I always wondered if it's not really going downhill until you get South of the equator?
I'm still not sure that levels really work since the would is not flat???
My '65 300ci L6 stock not rebuilt 107K miles, T18 4 speed, 3.50:1 rear, with Gear Vendors.
On recent trip from Nor-Cal down the to Atascadero, lightly loaded, all highway going 65-70 mph, 17 MPG.
Don't know rpm, yet to install tach.
Never made that same trip pre-GV but would estimate it would have been 13ish MPG+-.
I get 12-13 MPG with the truck packed HEAVY pulling the '62 Shasta (2,500 lbs) in the 55-60 mph range going up I5 to Lake Shasta. Of course, as my Dad used to say, that's going North which is uphill going South is downhill so you get better MPG
Although I always wondered if it's not really going downhill until you get South of the equator?I'm still not sure that levels really work since the would is not flat???
Cargo Master
Joined: Oct 2011
Posts: 2,214
Likes: 645
There is a formula to calculate rpm with the known tire diameter and axle ratio, however there is the gradeability factor people need to take into account. This is where the horsepower and torque of engine at reasonable rpm and weight of the vehicle and terrain ( flat land, hills, steep mountains) factors into your final calculations.
Thread Starter
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Fleet Mechanic
Joined: Jun 2019
Posts: 1,898
Likes: 234
From: Southern California
There is a formula to calculate rpm with the known tire diameter and axle ratio, however there is the gradeability factor people need to take into account. This is where the horsepower and torque of engine at reasonable rpm and weight of the vehicle and terrain ( flat land, hills, steep mountains) factors into your final calculations.
Now, on the truck, tire wear between new 31's and worn out ones the diameter will change significantly due to the thickness of the tread, and how slick I will drive on them.
Dan
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Thread Starter
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Fleet Mechanic
Joined: Jun 2019
Posts: 1,898
Likes: 234
From: Southern California
Well turns out that my foot forced my hand. Broke the spider gears in my 3.50 diff and had to pull my spare, which according to the warranty plate was supposed to be a 3.25-1. Well unless they changed math someone swapped a 3.70 in there. So the truck is on the road, but heading the wrong direction as far as the gearing goes.
I have my friend at the truck yard looking for a used TKO 500 or 600 as I would have to sell a project to buy a new one. Or I suppose I could do it the American way and get myself further in debt...
I have my friend at the truck yard looking for a used TKO 500 or 600 as I would have to sell a project to buy a new one. Or I suppose I could do it the American way and get myself further in debt...
Thread Starter
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Fleet Mechanic
Joined: Jun 2019
Posts: 1,898
Likes: 234
From: Southern California
Ok. The Tremec is out of reach financially. I'm over the 3ontree. Got a used T18 from my dismantler buddy for free so he wouldn't have to deal with my 3.03 transmission problems any more. Just got it in, everything fit fine. Used my original crossmember, mount, clutch, bell housing, speedo cable. I need a driveshaft before I can drive it and my high floor pan is in the mail. I guess I'm looking for a 3.00-1 rearend to get my freeway rpm's down, which was the original point of this saga.
More Turbo
Joined: Dec 2019
Posts: 734
Likes: 154
From: Orange County
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keyul
1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks
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Sep 14, 2009 11:48 PM