yes, i'm having all kinds of fun learning about drivetrain options... i want something other than a np435, to bolt up to a 351m, or a 460 whenever i get around to my engine change.

can anyone tell me about these newer standards? does the zf have an overdrive? what about this crazy 6 speed that has a low gear AND an overdrive ?? ??? ?

big $$$$$$$ i imagine...

 

ZF is a 5 speed manual overdrive transmission. ZF6 is a 6 speed manual overdrive with very low 1st gear.

 

The '91-96 ZF S5-42 (5-sp) has OD and a granny 1st.

 

I don't think you'd find a 6 speed with a bolt pattern to match the big block. (Someone jump in on this if I'm wrong)

The 5 speed ZF's with your bolt pattern do exist, but you're right about the cost. The money you'd save by sticking with the 435 would buy you an awful lot of gas.

 

I'm using the NP-435 with 3.08 gears & 32" tires to compensate for lack of OD. With its extreme low first (lower even than the ZF's), I don't have a problem taking off, even with a load. And since high ratio gears are stronger than low ones (like 4.10s), I actually have far less chance of breakage.

 

well was looking at this eearlier
you are looking for a wide ratio zf 5 speed and to make things easy the complete hydralic clutch back to the pedal off a 460 it has a 5.5+/- down a bit from the 6.58 first in the np235 granny gear

otherwise you will need to clearance knotch and extend the input shaft

the zf 6 speed is strictly a deisel thing

your pretty much looking for a truck that was hit in the front and rear then rolled right?

but on the good side you can keep you np205 gear driven t/c and the driveshafts will be the same length

 

are you saying that I have to alter the input shaft of the ZF 5 spd *unless* i use the hydraulic clutch assembly? or does it need modification regardless?

 

a manual clutch needs a longer through(shaft)
hydo shorter
also the clearance knotches are for the man clutch linkage and maybe np205 transfcase linkage
but yes hydo= no shaft mod

 

well, the cost of this option is gross, no matter where I look.. If i felt like prying a ZF out of a truck that was crushed into a cube, than it might be affordable.

SO i'm changing my mind. The truck will become an automatic. (I often make long haul runs that see me in top gear for hours at a time..)

Now i'm trying to come up with a transmission and diff gear combo. The engine is a 351M. If i move to a C6, i'm thinking I want 3.54's or 3.08's in the Dana 60 Full floater and Dana 44 HD that I'm running.

If I manage to come across a Beefed up AOD and can get an adapter plate, than maybe the 4.11's can stay, or I can change to 3.73 or 3.54..

Oddly enough, I even have a 300 six that i dont think would blow up the AOD I have that was originally behind a 5.0 in a 1988 LTD. I could easily gear up the TV cable, and it would all go in easily enough.

The main consideration is that the truck sees highway use, and I don't want to even come near 3000 rpm at 70 mph.

I wont even break 55mph how my truck is now, and usually dont break 50mph.

If y'all dont think (or know?) that I'm insane, I'd love to hear any suggestions ..

 

well am building out (bore/stroke) my 78 bronco's 351m(adding a 400 crank) to 427 and then swap with the rebuilt 351m in my 79 bronco that has a c6
for 325( +45 torqconv core +48 shipping for me cross country) you can get TEC HEAVY rebuild kit(HD frict/steel disc,kevlar band), "low stall" HD tourque conv transgo shift kit, 18k gvw trans cooler, hd high drum clutch and all seals bushings bearings gaskets

only one prob was thinking about going with a wide ratio roller kit for the c6
going from 2.46/1.46/1(:1) to 2.72/1.54/1(:1)
making it possible to goto a different rear gear and in final drive having the motor turn slower

well i will figure it out after i get it built and see how it acts

but back to the question at hand i wold try to fit a set of junk yard 3.73s or axles would be quicker swap

but np235(granny gear) and the c-6/c4 have the same high gear(4th or 3rd) of 1 to 1 thats why the zf is great it as a pretty low 1st 5.56 and a .75 5th
the aod has a 2.4 lo gear but a .67 od
if the zf was only cast iron or steel

 

well thats what i was getting at.. if i have a tranny with a 1:1 top gear, i'm thinking it's better to run the 3.54's or higher in the differentials..

i definitly need to maximize economy. if i get a tranny with an overdrive, than i'll see how it works with the 4.11's, before going a little taller perhaps..

maybe i'll get a c6 built with an OD add on.

J