I went cruising the local junk yard yesterday. I found 2 transmissions that are 4 speeds with (I think) granny 1st. I got the casting #'s so I could make sure. One of them says Borg Warner 13-01-065-904. From what I found it's a T18. Is this right? It's out of a 3/4 ton 2 wheel drive truck. The other tranny is a NP with casting # C-96391-S out of a 79 4x4 truck. Is this the NP435? And while we're at it, run it by me again what all I would have to change to swap from a TOD 4x4 to one of these. Which one would be better for towing with 3.55 gears and not over-rev my 302 at highway speeds? I have the 1356 BW transfer case.

 

There's not much to choose from between an NP435 and a T18. Very similar boxes, although a lot of people prefer the NP as smoother shifting. Both are nearly unbreakable and have very similar ratios. Both also have a 1:1 top gear which means you're going to be pulling more revs than you might like at highway speeds, around 2800 RPM @ 65 MPH with 29" tires. In terms of highway RPMs only the much less durable TMOD is a better tranny with those gears.

See:
http://www.fordsix.com/tech/trucktranny/trucktranny.htm

 

due to the fact that I own both trannys (T18 and NP435) I would tell you to get the np435 the t 18 is junk (mine is anyways) my np435 in my '75 F100 is (A) alot older then the T18 in the '89 and it shifts alot better and (B) I have NEVER had the shifter fall out of a NP435 but the T18 ..dont even ask..get the new process its a better tranny

 

Thanks for the replies. I'm trying to get this all straight in my head, so I can make an educated decision on whether to do the swap. I use my truck on a farm alot, pulling farm machinery and trailers. I also tow a 20 ft. pontoon regularly. I occasionally tow a 28 ft. camper in the summer and fall. Most of my driving is done where the speed limit is 55 in rural areas of VA. I haven't had any trouble out of my TMOD, I'm just looking for a more suitable towing setup. If any of this influences your opinions, let me know. Thanks.

P.S. My current tranny ratios are 3.29-1st, 1.84-2nd, 1.00-3rd, and 0.69-OD. This is from the limited info I can find.

 

I went back to the junkyard yesterday. I can get either one of these trannys for $75 each. (uncle-in-law is owner ) For this price, I thought about getting the NP for a spare even if I don't use it right away. They both seem to be in pretty good shape. What do these trannys usually cost from junkyards?

 

I paid $100ea for the last 2 NP-435s I bought.

 

Hey...i just found your blog about a transmission and a transfercase. hoping you can help me.. i too have a problem finding out what i have for a transmission.. mine says the same numbers..casting #'s C-96391-S and mine too has granny 1'st gear.. might this transmission be a NP435 out of a 79'? and as for the transfercase.. i have the numbers A1TWN2E as model number and 35509 A69 as the assembly number.. might you be able to tell me what year it might be.. or even where i could look to find out.. see here is my delema... i ahve a 79 351M with the same tranny. and this transfercase.. and i need a speedometer cable but nothing matches because i dont know what year eveything is.. any help would be great .. thanks -Brett

 

You look up a NP 435 online rebuilt from someone and it's gonna run you anywhere from 200 to 400 bucks if not more....I hated my t-18 and I believe the Np has a slightlylower first in it....as for getting good cruising rpms...you might wanna change your rear gears....that would help out loads......as for the 79 t-case on a post it's probly an np 205 with is an absolute DIAMOND do not get rid of it. and if you do get rid of don't sell it for cheap.....do some research......If I'm not mistaken....they didn't start the NP 208 until the 80's....on the back of the 205 should be a round red/silver tag...check that out it'll say 205 203 or 208...Keep in mind..the 203 is a full timetransfer case....the 208 is the 205's little brother....anyways....to the initial post...get the NP 435 and change your axle gearing.