I found a 300 6 with a np435/np205 combo locally for pretty cheap and I'm looking to swap the C6 on my current 460 to the 4 speed so my question is on the bellhousings.

1. I know the 351m/400m share a bellhousing with the 429/460 and that the 300 shares with the 302 and 351w but what I was wondering about was if the C6 has a detachable bellhousing. If it does that would make the swap easier because I've heard you need to grind the 351/400 bellhousing to fit the clutch when it's attached to a 460. Edit: I did a little more research and it looks like it's the C4 that has the detachable bellhousing.

2. I asked a friend about the bolt pattern attaching the bellhousing to the 4 speed and he said he thinks they are the same between the 300 and 460 but not 100% sure and neither am I so any help there?

The 460 in my truck is a 76 block if that matters and my current 4x4 setup is with a divorced t-case as well.

 

Yea, the C6 doesn't have a removable bell housing. The case and bellhousing are a single piece.

The 435/205 will bolt up to a 460 bell housing. Most 460's I've seen have had a T-19's. The NP435 doesn't have a synchronized first gear and it has a little steeper 1st gear ( which is why I like them! ) . But it will work behind the 460.

 

C6 bell is integral.

460 has 385 series bell pattern.

300-I6 has sbf bell pattern.

If I'm not mistaken, the np435 isn't super tough. Stock, the 460 probably won't break it. The 300 makes close to the same torque. Built at all, and I'm not so confident. The old sm420 is rumored as bullet proof, and I've got a buddy with a broke one. Broke it with a way mild BBC in a 65 C10 thats just a hot rod. I certainly could be wrong though.

Either way, doesn't the 435 have a removable bell? The aftermarket will have the bellhousing you'll need. I don't know what applications from the oem fits your needs but no doubt someone will know where to look as far as junkyard parts if they will work.

 

That's what I was looking for thanks. I found the 300 with the 435/205 for $200, I'm going to give the guy a call tomorrow.

I looked at the T-19 but everyone I talked to and most things I read online leaned towards the np435 are there any advantages between either one? I like the steeper gear too but why do you like it more since it doesn't have a syncronized 1st gear?

I've been playing with the idea of switching the rear end from the dana 60 to a 44 when I swap to the np435, I have 3.54 gears in it now and I figure I get around 10 mpg with normal city/highway mix, I'd like to get 12-15 I only tow a little and it's usually just hay wagons but I figured if I switched down to smaller gears like a 3.07 or 3.25 and couple it with the steep 1st gear I could still have towing power and get decent mileage on the highway but I don't know much about rear end gear ratios and how they affect towing/mileage so any ideas there?

 

The NP435 is a tough transmission. Ford wouldn't have ran them in F600's if they weren't! But if you abuse them they can break just like everything else. I drive my vehicles like I stole them and I've never broke one. But I don't have a built 385 stroker motor with 44" tires on my trucks either.

He was asking about the transmission bolt patterns on the bellhousings not the engine side.

 

I'm not sure on its strength, some people say it's bullet proof others say not so much. A buddy of mine had one in his 78 with a 400 and it was fine for him but the 460 does make more power. I'll look into the one you mentioned though.

The 460 won't get built too much, when I get enough money put aside for a rebuild I will just go back to pretty much stock except for maybe a mild cam, edelbrock performer intake and set the timing straight up to get rid of the 4 or 6 degree retarded timing whichever it is.

 

What part of Minnesota are you from? If you get the 300 and don't want it you can drop it off at my place!!

The T-19 is slightly stronger then the NP435. Which is why the came behind the 460's and diesels. The non-synchronized 1st doesn't bug me. I'm usually stopped when I drop it into first gear anyways. I'd rather have the 6.69:1 first gear over a synchronized first gear.


I don't think I'd swap out a Dana60 for a Dana 44. That's taking a big step back in the strength department. I don't think a taller gear is really the way to go. Have you given any thought to swapping in a ZF 5spd to get OD 5th gear?


Oh yea and I've hauled 14,000+ pound loads with a truck that had a NP435 with over 250,000 miles on it with no problems. So that tells me they are plenty strong. I'm going to run one in my 54 F100 project truck and I'm swapping one into my 89 E350 van.

 

I have but I'd like to keep it more stock and have the 4 speed plus I don't want to take the time to set up a hydraulic clutch, maybe sometime in the future but right now my budget isn't high enough to afford a ZF and all the stuff for that.

The strength of the dana 60 is why I haven't swapped it already, I think everyone who has a 460 will always think of different ways and random ideas on how to improve mileage.

I'm from around the Grand Rapids/Deer River area and I'd probably take you up on that. I don't have a use for the 6, where are you at?

 

I think you could make the mechanical linkage work on the 460 ZF 5spd. It's been a few years since I had one but I'm pretty sure they have the external slave cylinder with a clutch fork. Not like the small block ones that have the stupid hydraulic throw out bearing. It gives you something to consider in the future.

I've owned a few 460's. 460's and fuel mileage don't really go hand in hand. All the ones I owned seemed to get right around 10 mpg. It didn't matter if it was empty or loaded it got around 10 mpg!

Damn! I'm on the other end of the state. I'm a half hour south of the Twin Cities, 8 miles west of I-35. I'm a big fan of the 300's!

 

Half hour south huh, I'm going to the tech school in Red Wing until may. Maybe this summer I'll make a trip down with it, if I end up with it that is.

 

Sounds like a plan to me!

 

All 1968/82 460's came with C6's. 1983 was the first year FoMoCo offered the 460 w/a M/T (and 4WD).

All 1983/97 F250/350 460's came w/a hydraulic clutch.

460 not available in F100's after 1976, not available in Passenger Cars after 1978, not available in F150's after 1979.

Bell housing: M/T / Converter Housing: A/T / C6 converter housing made as part of the trans case.

 

no 460 came with a manual trans before the 80's. later 460's did come with the zf trans but those engines were balanced differently so flywheels don't swap over. Only flywheel that works is an aftermarket one unless you can find an old boss 429 flywheel but good luck with that. Some people have used 390 flywheels but they have a few teeth less than the 460 uses. Some have reported chewin up teeth and others found little to no problem. As far as the 4sp. goes just put the right bellhousing on it.

 

I know about the years the 460's came in trucks and that they didn't have manuals in the 70's that's why I was asking about bolt patterns for the bell to the tranny which was already answered

Doesn't a 390 starter fit the 460 bellhousing? Seems like that would be the ideal thing to do if you are going to swap in a flywheel with les ot mroe teeth.

 

ive done over a dozen auto to manuals or manual to auto swaps... i run a rebuilt np435 behind a turbo 6.9 deisal in a 78 supercab... it holds up plenty fine.. all the np435s and t-18 or t-19s us ethe samw tranny to bellhousing bolt pattern...the 390 flywheel on a 460 does work but theres a couple hang ups..