I have a 1968 Ford F100 with a 300 six and a NP435 trans. What would be a suitable swap to a 4 or 5 speed trans with overdrive? I am not happy with the large gaps in the ratios between gears with the NP435 tranny and am looking for a fully syncronised tranny. My rear end has a 3.73.

 

anything that had a 302 5 speed can be made to work, expect to have to convert it to a hydraulic clutch and other odd expenses that will come up.

 

Didn't Ford offer the 300 six with an optional 4 or 5 speed overdrive transmisson at some time? My manuals list the transmissons as optional, but do not refer to the specific model make or number. Consulting manuals are Chiltons, Ford F series Pickup Owner's Bible, and Catalog of Ford Truck ID Numbers 1946-1972. I would like to find a swap that would be as simple as possible. The thing that bothers me the most about the NP435 is the wide spread between 3rd and 4th. The previous owner of this truck used it for pulling a camper for which the NP435 is probably well suited for, however I use it mainly for commuting on the freeway. I know I could just get a car, but what can I say I like driving these old trucks. A friend suggested that I should use a 3.03 trans and change the rear-end to a 3.5 or taller ratio. Can the NP435 ratios be changed to a close ratio gearbox eliminating the compound low gear?

 

If your truck is having problems with not having a ratio between 3rd & 4th, will it even have enough power to make use of an overdrive? What about the absence of the granny 1st when taking off on a hill from a dead stop. Even the 390's and 460's make use of that gear at times. The only other alternative would be to burn the clutch.

 

300-L6's are built for lugging power. You allready have one of the toughest fully syncd. trans ever made(except 1st & rev.)
I know what ya mean. Topping out at at 28mph in 3rd. Thats what mine dose anyway.
The 300-L6's don't have much HP. They're designed to produce
torque. I think the HP output is 145HP. (somebody corect if not true.) You lose significant HP at the flywheel. Even more by the time it gets to the wheels. Or BHP. The actual force put to the ground threw the tires. So by puting in a higher geared trans
you will have alot of low end power loss. But you will gain speed
and mpg. That can be accomplished with taller tires or higher
rear gearing.


Garett

 

I read somewhere that there are close ratio 435's out there. I'll try to find that article when I get back to work.

A friend of mine at work has got a late model F-150 (95 I think), it's got a 300 and 5-speed, so it shouldn't be too tough a swap.

BFM

 

Thanks for the replies. It's not so much that I want a higher geared trans, I would just like another gear between 3rd and 4th. That big gap is just no good when your trying to get on the freeway in L.A., these guys are just not going to wait for you to get up to speed. I thought perhaps a close ratio 3sp or a T-10 in combination with a higher ratio rearend might be the answer.

 

I also thought that the NP435 came in optional close ratios, but I can't find the article or reference. I saw from my reading that there were optional 4 and 5 speed overdrives available I just can't identify the specific models.

 

Oh You want to run like a big truck, huh. Snach that pueny one legged I6 out, and install a 390/C6 with a 3.00 rear gear and they wont have to wait on you any more.

All them little motors are good for is scrap weight anyways. Oo Oo Oo

John

jowilker
[link:www.ford-trucks.net/users/jowilker|Club FTE since 01 01] My FTE Page

[link:www.ford-trucks.net/users/jowilker/NCFTE.html|NC Truck Owners] NC Ford Truck owners group

66F100s Rule
In the cool still quiet of night you can hear chevies rusting away.

 

Now John! Don't discourage me. LOL



Garett

 

Come on now Jowilker, I guess you've never seen those little Offenhauser 4 cylinders run. They were so fast and made so much horse power that they were made illegal in races just to give the V8's a chance to win. Besides anyone can make a V8 run where's the challenge in that. Check out the August issue of Custom Classic Trucks to see what a 300 can be made to do.

 

Yeah I guess you are right, funny thing though every time I see one of those top fuel dragsters, they have one on them 4 cylinders for both sides, so you may be on to something.

Maybe I could get DF or FE427 to weld me up two of them squirrels and make me a V12, and put some of the stuff that you are talking about on there and really get a testosterone rush. arg arg arg.

John

jowilker
[link:www.ford-trucks.net/users/jowilker|Club FTE since 01 01] My FTE Page

[link:www.ford-trucks.net/users/jowilker/NCFTE.html|NC Truck Owners] NC Ford Truck owners group

66F100s Rule
In the cool still quiet of night you can hear chevies rusting away.

 

[font size="1" color="#FF0000"]LAST EDITED ON 16-Jul-01 AT 01:10 AM (EST)[/font][p]That's not very fast, I have 4.11's in my truck and run 235/75/R15's and I can get to 60 in third with the NP435 it's right around 5300RPM and I'm shifting right there I really hate spinning a 360 that hard.