I have a '55 Dodge P/u with a '64 Poly 318 (A-motor) backed by an NP435 -granny low (6.69:1) trans out of an W200. The truck has been in my family since new, originally a 259/ 4-speed, it has led a tough and overworked life. Gramps put the Poly in in the late 70's. I recently pulled the clutch, at an opportune time too, it’s a mess! Stress cracks around the rivets and the center of the clutch disc is acually torn around the springs in a few places. After searching high and low the local NAPA guy finally tracked a clutch down for me when none could be found and its gonna set me back around $500 when all is said and done. Well, being the poor guy I am I'm thinking this might be a good time to take the NP435 out and put something more updated or conventional behind the Poly. The 435 is the 10 spline input variety. So, what are my options? I'd like to stay with a manual and cost is an issue, as always. Thanks
I think the main problem is the flywheel and bellhousing in the old trucks are kind of weird....and the bellhousing mounts to the crossmember. the transmission is probably a NP420? but that's just a guess. You might be able to use a newer transmission (NP435) and bellhousing and flywheel from a 1970s-80s era truck, but you may have to make a rear mount for the transmission, and not mount the bellhousing to the crossmember. At least, that's what I'd look at first.
One would think that since the back of the post-'62 318 Poly is the same as a regular 'ol small block Mopar, and that there's several small block equipped trucks with the NP435 (over several, several years) that your clutch choices wouldn't be so reduced.
Squirrel, your right about the bell mounting ears and that bell weighs a lb or two. I don't mind fab-ing up a cross member and mounts, more concerned with what it may take to fit a different trans. Abomination, apparently the problem stems from the 10-spline input shaft, most others are standardized at 23-spline. Though, there may be other diffs that I'm not aware of. You being the resident "Poly Guy," I knew you would be here to lend a hand. I've been searching for the last few days and caught wind of some that have mated a Dakota ax15 and nv3500 and 4500 series trans' to Polys. Anyone have any info? I haven't been able to find anything sold. Thanks.
Talk to this man: http://www.jalopyjournal.com/forum/members/73rr.26736/ He's done many Early Hemi to Dakota transmission experiments. The Early Hemi and the '57 - '62 318 Poly have the same rear engine. 73RR makes Hemi adapters, etc that allow them to be bolted to anything a small block Mopar can. Since you already have a regular small block Mopar rear on your '64 Poly, you're already there! Hit 'em up for some info on his Dakota experiments. He may also have the parts for sale that you need to swap one of those transmissions into your ride (or know what and where to get). Plus, he's just good people! ~Jason
Don't know if this will help you but a friend has a early Dodge with the flat heat six cyl. He recently adapted a s-10 5 speed and said it went in pretty easy. Now is the six the same bolt pattern ect as the Poly?
nope, completely different. Although some of the old bellhousings from trucks will work with a few different engines (they have lots of bolt holes!)
If you need or want a full sized truck trans, try and find an NP-445 instead of a 435. All synchro and much better ratios. 4.46 first and third is a great p***ing gear. Found in '70's era Dodges, it was an option. Why not just put in a T-Flyte?
Any of the modern Dodge truck (including Dakota) standard V8 or V6 transmission bell will bolt up to your 64 poly. Once the bell is there, the matching trans bolts on as well. You will need to fabricate a trans crossmember, I'd remove the original bell mounting system. You can use the clutch that matches the trans/bell and probably the flywheel, if you can get is zero balanced, and it has the proper number of mounting bolts. The modern hydraulic linkage setup makes things a lot easier to attach to your truck. I really like my 5 speed AX15. Gene
what 50dodge4x4 said - you have a late poly 318 - don't worry about the spline - you'll change that out easy enough - if you can find the mid 70's 4 speed OD based on the 833 trans or go with a later 80's mopar 5 speed - might have to have the hydraulic bell housing.....and what Squirrel said -fab some new rear mounts.....
Since the engine is in a 55 Dodge pickup then any of the many late model designs can be used and the needed mounts fabricated, probably as has been done for the current installation. Options will include an A-833, either 3+1 OD or 4-speed; AX-15, (not AX-5...); or any of the one-piece NV series. Any mounts at the bell housing can be eliminated during a swap since all of the 'usual' candidates will have a trans crossmember. And yes, all of the late model stuff uses a hydraulic slave arrangement. The OP just needs to consider the gear splits and what he likes in a driver. .
Anything with a LA bell-housing....It's a beauty! even new hemi engines / 5.7 liter / even V10 if i remember right are all using the same bell-housing. teeths, starters and flywheels etc..not sure.
I can't speak to the V-10...haven't actually looked at that one but it doesn't seem to 'feel' right. The 4.7 also uses the LA bell pattern. As to flywheels, most of the new stuff uses an 8-bolt but on a much smaller bolt circle than previous 8-bolt patterns. The 6-bolt pattern was used on the 3.9, 5.2, 5.9. AFAIK, the rest use a different pattern. Corrections to this are appreciated. .
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