Go Back   The Ford Barn > General Discussion > Early V8 (1932-53)

Sponsored Links (Register now to hide all advertisements)

Reply
 
Thread Tools Display Modes
Old 05-24-2019, 09:46 AM   #1
melisahe
Senior Member
 
melisahe's Avatar
 
Join Date: Aug 2013
Location: new orleans
Posts: 198
Default 49 f1 PU T5

current project 49 f1. Thinking of putting in a T5 transmission to gain highway speed (70mph). Will I be able to cruse at 70 with my flathead and the T5? How feasible is it? Will I need frame modification? Thanks for any input. I did a thread search and got no results. Truck currently has original four speed.
melisahe is offline   Reply With Quote
Old 05-24-2019, 10:06 AM   #2
corvette8n
Senior Member
 
corvette8n's Avatar
 
Join Date: Jul 2010
Location: 36 miles north of Albany NY
Posts: 1,666
Default Re: 49 f1 PU T5

70 mph is over rated in a 70 yr old vehicle, slow down and enjoy the ride.
corvette8n is offline   Reply With Quote
Sponsored Links (Register now to hide all advertisements)
Old 05-24-2019, 11:19 AM   #3
GreenMonster48
Senior Member
 
GreenMonster48's Avatar
 
Join Date: May 2010
Location: Enfield Connecticut
Posts: 559
Default Re: 49 f1 PU T5

Unlike the guy above me, I’ll try to be more helpful. Yes it’s possible to go 70 in overdrive. What rear gear ratio do you have/want. You will need to cut the crossmember as the T5 is longer. Many people sell adapter kits for Flathead to T5
GreenMonster48 is offline   Reply With Quote
Old 05-24-2019, 11:27 AM   #4
JSeery
Senior Member
 
JSeery's Avatar
 
Join Date: Nov 2012
Location: Wichita KS
Posts: 12,605
Default Re: 49 f1 PU T5

Frontal area is always going to be an issue, but not really anything you can do about it. RPM with a given combination of OD gear ratio, rear axle ratio and tire size is easy to calculate. If it was me, I would want to keep the RPM high enough at cruse speeds to not load the engine, but this can be very subjective.
JSeery is offline   Reply With Quote
Old 05-24-2019, 11:52 AM   #5
Bob C
Senior Member
 
Join Date: May 2010
Location: So Cal
Posts: 6,336
Default Re: 49 f1 PU T5

Since you currently have a 4-speed you may not need to cut the cross member.


Bob
Bob C is offline   Reply With Quote
Old 05-24-2019, 01:08 PM   #6
melisahe
Senior Member
 
melisahe's Avatar
 
Join Date: Aug 2013
Location: new orleans
Posts: 198
Default Re: 49 f1 PU T5

The truck has the original rear end at present. I have a ford 9 inch out of a 78 ford. I don't want to go radicle, Just don't want to do 45-50. Maybe keep original rear end?.
melisahe is offline   Reply With Quote
Old 05-24-2019, 01:10 PM   #7
38bill
Senior Member
 
38bill's Avatar
 
Join Date: Apr 2014
Location: Minnesota
Posts: 695
Default Re: 49 f1 PU T5

My '38 has a T5 and 3:54 banjo rear end. 70mph is no problem but its noisy. I don't know about frame modification but you may also have to change the driveshaft. If you are planning to go that fast you will also want to make sure that the front end is in good shape and that the brakes are up to snuff.
38bill is offline   Reply With Quote
Old 05-24-2019, 02:11 PM   #8
melisahe
Senior Member
 
melisahe's Avatar
 
Join Date: Aug 2013
Location: new orleans
Posts: 198
Default Re: 49 f1 PU T5

Thank you for the replys. The truck with have new brakes all the way around and I'll be changing any front end part that looks suspect. Many test drives and power stops to make sure all is OK .
melisahe is offline   Reply With Quote
Old 05-24-2019, 03:03 PM   #9
Pete
Senior Member
 
Pete's Avatar
 
Join Date: May 2010
Location: Wa.
Posts: 3,385
Default Re: 49 f1 PU T5

Quote:
Originally Posted by melisahe View Post
current project 49 f1. Thinking of putting in a T5 transmission to gain highway speed (70mph). Will I be able to cruse at 70 with my flathead and the T5? How feasible is it? Will I need frame modification? Thanks for any input. I did a thread search and got no results. Truck currently has original four speed.
Yes, it will work fine, but keep in mind, with a stock engine and the wind resistance of a truck, you only have about 90 to 100 hp so at 70 even with ideal gearing, your gas mileage is going to suffer.

Yes, you will need to do some modification to the frame and driveshaft.
Pete is offline   Reply With Quote
Old 05-24-2019, 03:11 PM   #10
4t8v8
Senior Member
 
Join Date: Nov 2011
Location: NW Arkansas
Posts: 490
Default Re: 49 f1 PU T5

My 48 F1 was a 3 speed. Had to cut the center out of the rear cross member and brace it back to the new cross member I fabricated as the brake and clutch pedals mount to the original cross member. Had to shorten the drive shaft and be sure it was correctly aligned. Bought a kit from Cornhusker. It made the bolt up part easy as everything you will need is in the kit. Was the swap easy? No. Was it worth it. Oh my YES. Mine has 3.78 gears and cruises at 60 - 65 all the time.
4t8v8 is offline   Reply With Quote
Old 05-24-2019, 04:10 PM   #11
Ol' Ron
Senior Member
 
Ol' Ron's Avatar
 
Join Date: May 2010
Location: Chester Vt
Posts: 6,883
Default Re: 49 f1 PU T5

There's an adapter out there that cost only 160 dollars and allows the T5 to bolt to the stock Passenger bell housing and uses the stock clutch linkage. But I don't think a stock engine can handle 70 mph. It just doesn't have the power for extended running.
Ol' Ron is offline   Reply With Quote
Old 05-24-2019, 05:29 PM   #12
expavr
Senior Member
 
expavr's Avatar
 
Join Date: May 2010
Location: Hansville, WA
Posts: 679
Default Re: 49 f1 PU T5

I replaced the 4 speed in the Tonner with a 49 Merc 3 Speed O/D trans behind a 239 CI engine and a set of 4.11 gears driving 30” Michelin M/S tires on the Tonner and it cruises nicely at 60-65 MPH. The sweet spot for me is closer to 60 MPH where you feel like you can enjoy the ride with less concern about the vintage brakes and steering. I’d say go for it you won’t regret it.
expavr is offline   Reply With Quote
Old 05-25-2019, 04:23 AM   #13
GreenMonster48
Senior Member
 
GreenMonster48's Avatar
 
Join Date: May 2010
Location: Enfield Connecticut
Posts: 559
Default Re: 49 f1 PU T5

Quote:
Originally Posted by melisahe View Post
The truck has the original rear end at present. I have a ford 9 inch out of a 78 ford. I don't want to go radicle, Just don't want to do 45-50. Maybe keep original rear end?.
If you go with a T5, you can probably keep your stock rear. 9 inch rear from 57-72 F100 are the easiest to swap in as they are the same width and spring perches are in the right spot. 78 ford rear is 3 too wide if its out of a truck.
GreenMonster48 is offline   Reply With Quote
Old 05-25-2019, 04:26 AM   #14
GreenMonster48
Senior Member
 
GreenMonster48's Avatar
 
Join Date: May 2010
Location: Enfield Connecticut
Posts: 559
Default Re: 49 f1 PU T5

Quote:
Originally Posted by Bob C View Post
Since you currently have a 4-speed you may not need to cut the cross member.


Bob
He will. Stock Borg Warner crash box 4 spd is the same case as the HD 3 speed
GreenMonster48 is offline   Reply With Quote
Old 05-25-2019, 10:29 AM   #15
Bob C
Senior Member
 
Join Date: May 2010
Location: So Cal
Posts: 6,336
Default Re: 49 f1 PU T5

I thought the 4-speed used a different cross member but after looking in the parts
book I see it only shows one cross member for the F1.


Bob
Bob C is offline   Reply With Quote
Old 05-25-2019, 05:32 PM   #16
Ol' Ron
Senior Member
 
Ol' Ron's Avatar
 
Join Date: May 2010
Location: Chester Vt
Posts: 6,883
Default Re: 49 f1 PU T5

The stock 239 engine in good tune only produces aprox, 80 HP less fan and generator load. This is at 3200 rpm. AS noted in jWL's book. Dull exhaust doesn't improve it much. Advertised Horsepower numbers are the figment of the sales department imagination
Ol' Ron is offline   Reply With Quote
Old 05-26-2019, 09:56 AM   #17
melisahe
Senior Member
 
melisahe's Avatar
 
Join Date: Aug 2013
Location: new orleans
Posts: 198
Default Re: 49 f1 PU T5

is the six rated at 90HP a figment also?
melisahe is offline   Reply With Quote
Old 05-26-2019, 04:45 PM   #18
Ol' Ron
Senior Member
 
Ol' Ron's Avatar
 
Join Date: May 2010
Location: Chester Vt
Posts: 6,883
Default Re: 49 f1 PU T5

??????? Probably!!
Ol' Ron is offline   Reply With Quote
Old 05-26-2019, 06:10 PM   #19
JSeery
Senior Member
 
JSeery's Avatar
 
Join Date: Nov 2012
Location: Wichita KS
Posts: 12,605
Default Re: 49 f1 PU T5

There were using new engines.
JSeery is offline   Reply With Quote
Old 05-26-2019, 06:11 PM   #20
TomT/Williamsburg
Senior Member
 
TomT/Williamsburg's Avatar
 
Join Date: May 2010
Location: Williamsburg, Virginia
Posts: 2,212
Default Re: 49 f1 PU T5

My avatar has a T5 and I’ve done 85 with it ......
TomT/Williamsburg is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Sponsored Links (Register now to hide all advertisements)


All times are GMT -5. The time now is 03:01 AM.