SM465 and NV4500

[my67c20]

I could not help notice how similar the SM465 and the NV4500 are. Has any body looked to see if you can just swap out the top cover and add the tail shaft housing to the SM465 and achieve the NV4500. Sure would make the swap cheaper and easier. No messing with the clutch or the bell housing. Would still need to modify the drive shaft and the floor, but heck that's the easy part.

[BurnoutNova]

The top shift plate is not the same. Besides, if you have the 5th gear housing and shift plate you probably have the entire nv4500, just swap the whole thing?

[SS Tim]

The spacer plate AA sells to install a Dodge NV4500 to the stock manual bellhousing (and clutch linkage) in our trucks is about as easy as it gets. Not sure if the clutch disc has to be replaced though it has been awhile since I looked into it.

[JJorgensen52]

If you purchase a GM NV4500, it will fit your stock clutch and pilot bushing.

The internal shift linkages are significantly different, and the rear of the NV4500 case will not even remotely come close to fitting the SM465 housing. The similarities exist because the NV4500 was designed and intended to replace the SM465 when the GMT-400 3/4 ton trucks came out in 1993.

Advance Adapters 712577 (1992-1995) or 712576 (1996-2003) bellhousing mounts the GM NV4500 to a small block or 6.2/6.5 detroit diesel with a standard mechanical clutch linkage. They run about $400.

In order to do this swap you need to switch to a block mounted starter and change driveshaft length as noted.

This image shows the adapter bolted up with the new clutch fork just prior to installation in the truck. I retained my stock clutch and linkage. This is a 1995 GM 4wd unit, note the bolt on shift tower.


There are 4 different NV4500 variants:
'93+ Dodge - 5.61 first gear, 7.625" x 1-1/8" input shaft, .750" pilot diameter
Dodge HD (diesel) - 5.61 first gear, 7.625" x 1-1/4" input shaft, .750" pilot diameter
'93-'94 GM - 6.34 first fear, 6.625" x 1-1/8" input shaft, .590" pilot diameter
'95+ GM - 5.61 first fear, 6.625" x 1-1/8" input shaft, .590" pilot diameter

All of them have a 10 spline input shaft. The top cover for '93 and '94 has a cast-in shift tower, after '95 the shift tower is a bolt on unit.

GM cases '93 - '95 have a GM specific bolt pattern, GM cases '96+ share the same pattern as Dodge.

By far the simplest way to do this swap is a GM box with the AA bellhousing; this uses a standard throwout bearing, pilot bushing and clutch fork. If you are okay with a hydraulic clutch you can use the GM bellhousing from the donor truck. The Dodge versions use different throwout bearings.

If you shop around a bit you can pick up an NV4500 for less than $700 in good shape. High Impact Gear and others will sell you a professionally rebuilt GM box with whichever first gear you want and all the latest updates for around $2k

You will also find that unless you're wheeling or doing HEAVY towing, the 5.61 first gear is a lot more useful. Your SM465 has a 6.55 first gear.

[SS Tim]

Like I said AA does still have their plate adapter for the early Dodge NV4500 allowing you to keep the stock bellhousing and mounts. But there are throwout bearing and pilot bushing issues to address too.
#712550 Dodge NV4500 5 speed transmission to a GM V8 adapter plate kit.
http://www.advanceadapters.com/produ...ter-plate-kit/

[Vintage Windmills]

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[my67c20]

Definitely appreciate all the feedback and part numbers. I was looking into doing this years ago, but then got thinking about the 700r4, then my mind and my potential budget wandered. Recently changed the rear to a 14bolt with locker and 3.73 gears, so spent allot of time on the suspension and was not really looking forward to the modifications to add an automatic, so my thoughts are back on the stick. For those that have done this, how much total and time did you put into this.

[JJorgensen52]

Originally Posted by my67c20

For those that have done this, how much total and time did you put into this.

I don't really count time spent doing internet research or waiting for parts to arrive, but:

$750 - NV4500 with shifter and cross member from '95 GMC diesel at my local dismantler
$400 - AA bellhousing
$80 - new starter
$380 - new driveshaft with new 1350 yokes for trans and rear axle
$100 - miscellaneous (throwout bearings, hardware, trans mount, etc)

So bottom line, about $1700 in parts (I also had a front driveshaft and a T-case but that doesn't matter for you )

I had a week off from work and was able to get it all done including driveshafts and fabbing up a new cross-member working by myself. I also was dumb enough to install the clutch disc backwards the first time around so I had to pull the trans out of the truck a second time

I should also note that I have put right around 10k on my swap thus far, I tow 6-7K fairly frequently and plow all winter, and my NV4500 is holding up just fine despite having about 400k on it when I bought it and having some slop in the main bearings. I'm going to rebuild it when I pull the motor hopefully later this summer.

Also of note, the stock NV4500 shifter does not work particularly well with stock bench seats, it's really tough to get into reverse or 2nd. You can buy a steel shifter to bend to whatever shape you like, I've seen them on Summit and some other places.

[kwmech]

The main case, top cover are both entirely different engineering. Parts are not going to 'interchange'

[Theboatandcarman]

so it looks like i will not be able to use the factory mounting which is the bellhousing transmission mounts? looking at doing my 68 c20

[LockDoc]

Originally Posted by Theboatandcarman

so it looks like i will not be able to use the factory mounting which is the bellhousing transmission mounts? looking at doing my 68 c20

Yes you can, if you use the GM NV4500. I did it on my '72 C-30 and used all of the original manual trans parts & linkage....

http://67-72chevytrucks.com/vboard/s...d.php?t=673588

Now I can cruise 70 on the interstate with no problem and still have the granny low. Best of both worlds...

LockDoc