View Full Version : GM465 4-speed to 12v CTD??
06-16-2007, 04:17 PM
Sounds crazy huh?
Is it possible? Anybody attempted this? sources for adapters?
06-16-2007, 04:45 PM
I think it is if you used one from a big truck (c40-80) and used a SAE bellhousing behind the ctd. The big truck 4 speed has a monster input 1.5" (I think) compared to the pickup truck 1.125", it is much longer than the little chevy shaft as well, and has a bigger pilot size as well. The clutches used in these setups are massive and ceramic button versions are commonly available. The flywheels that were used were approximatly 50-60 lbs on gasser versions. Parts from the old big trucks can be had for next to nothing oftentimes.
06-16-2007, 05:00 PM
hmmm, something to think about i spose.
Reason i'm interested/curious, is the 727 in my CTD (in another post: trans options) is roached and i need a good replacement. I'm totally new to dodge transmissions.....but i have 3 spare GM 465 trannys sitting in the shop, awaiting use.
Figured if they would work, maybe i should just "use what i have" so to speak
06-16-2007, 06:37 PM
I know that there is an adapter for a cummins to a chevy bellhousing, they put 4BTs in frito lay vans. they came with a chevy turbo 400, Im not sure of any good source for that adapter but I heard they were expensive, good luck
06-16-2007, 08:30 PM
there's 2 adapters on ebay, but i dunno if they would work for a SM465.......
06-16-2007, 11:17 PM
Keep us informed of what you find; as, I have a 1978 K-20 Chevrolet, with the SM465 and NP205, in line for a 1st Gen. Cummins transplant.
Those old Chevy 4-speeds are pretty much bullet-proof.
I also have an entire 1964 50-series GMC, with the older version 4-speed (the one with 7.something to one first gear), and a big-block V-6 GMC truck engine.
I may borrow some strategic pieces from the larger truck.
I would love to restore the old 64 GMC, but it appears that rust may have gotten the upper hand on this one.:(
I would have to cut a few trees out of the frame, as well.[laugh]
06-17-2007, 02:30 AM
I have a friend who works the counter at Cummins Rocky Mountain, he priced all the components needed for this exact swap at around $1300. This includes engine adapter, bellhousing adapter, flywheel and the starter, he said some of these parts can be had used off of core engines for a sustantial savings. I have the Cummins print out in my shop, I can post part numbers if you want them.
06-17-2007, 07:52 AM
I have the Cummins print out in my shop, I can post part numbers if you want them.
That would be AWESOME, YES i'd like the part numbers
06-17-2007, 06:31 PM
Theres a guy on 1stgen.org with a 4bt backed by a 465. He was asking about compounds on a 4bt, you might find him for questions you may have.
06-17-2007, 09:41 PM
thanx, will give it a shot
06-18-2007, 06:37 PM
Here are the part numbers I have for this conversion. Looks to me that you would be ahead of the game to find a Getrag/NP205 combo, the transfer case has the front axle output shaft on the correct side for a Chevy and you gain an over drive gear. The SM465 does have a 6.7 to 1 granny gear and is a stout tranny, however the NP205 that goes behind the SM465 has smaller input/output shafts than the one that goes behind the Getrag.
I am putting a Cummins in an 85 Blazer and considered using the GM tranny transfercase untill I saw how much the parts were. Best of luck,
3910516 Transmission Adapter 289.96
3906803 Flywheel Reman/Used 400.00
3913056 Flywheel New 870.34
3934080 Spacer, Starter Motor 72.43
3906804 Cover, Flywheel Housing 276.11
3916101 Cover, Flywheel Housing 648.34
Cover Flywheel Housing=Bell housing I think.
3964432NW Starter, Denso, 12V, 268.84
06-18-2007, 07:38 PM
The money you save on the swap will probably be lost in fuel economy especially if you do some freeway driving. Just a thought. Jethrro
06-19-2007, 02:45 AM
thanx for the parts numbers!
06-19-2007, 06:58 AM
You may also be interested in looking around at http://4btswaps.com for other transmission options. The 4BT & 6BT share the same engine adapter & bell housing configuration. The weakest point would be 11 inch clutch used in the 4BT.
06-19-2007, 01:01 PM
Alot of the 4BT bread vans had the SM465 so that would be a good source for the adapter and parts needed. The starter is on the wrong side. It also clocks the trans at a wierd angle. I just sold mine on ebay for $600, there is usally a few on there.
06-19-2007, 05:09 PM
thanx for the link to the 4bt swap forum, ALOT of useful info there!!
06-19-2007, 06:00 PM
The 4BT & 6BT share the same engine adapter & bell housing configuration. The weakest point would be 11 inch clutch used in the 4BT.
Could not one bolt a 6BT flywheel on the 4BT engine and then use the 13" clutch??
06-19-2007, 06:26 PM
not sure on the interchangability, but something i am checking into.
I was going to ask basically the same question about the clutch/flywheel, but i am still waiting to be "approved" to post over there :(
06-23-2007, 08:12 PM
Check this out:
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