th350 to 5 speed manual

[popsthebuilder]

I guess I'm kinda strange but I would love a 5 speed in my 73 c20 350/ th350 camper special. I've always preffered the level of control that you get from a manual. I'm almost positive there is a thread about this already. Does anyone know were to look for a thread pertaining to this or something similar? Does anyone know what 5 speed would bolt up with minimal modifications to my truck?  Also what transmition would handle 350- 375 hp? Thanks.

[Captkaos]

The native search here stinks(yeah, I said it)...  I typically go to google and type for this example:  5 speed site:73-87chevytrucks.com
This will find all of the references to that.
With that said, what is the intended purpose of the vehicle?  Are you talking about 350-375hp or torque, that would be a fairly healthy motor....
If you want a manual, the easiest is a SM465 granny 4 speed, that is what came in these.
Otherwise if you are going to be just driving it and not abusing it the NV3550 out of a 92-98 fullsize will work, or the NV4500 if you want a SM465 with overdrive and need the gearing.

[popsthebuilder]

I will definitely be putting it under a good load quite often. I use it for work.

[popsthebuilder]

I asked about the horse power because I've been talking with a good engine guy who says he can bore original engine .30 over and rebuild with somewhat performance parts for around $2000 parts and labor. When asked he stated that the engine would put out from350- 375 hp once completed. So 5 forward gears that can take a beating is out of the question?

[Jason S]

So 5 forward gears that can take a beating is out of the question?

You can have a 5-speed, based on what you indicated, it would just need to be the NV4500. 

[popsthebuilder]

Is the nv4500 computer controlled? How would I go about bypassing any computer controlled aspects if so. I found a wrecked 2500 with a rebuild transmission.  What would have to be done for a transmission in a 4x4 to work in my c20?

[Jason S]

Is the nv4500 computer controlled?

No. It is a manually shifted gear drive transmission with 5 forward gears. It's essentially a granny 4-speed transmission with an overdrive. The transmission was offered in computer controlled vehicles, but the computers do not operate the shifting. 

What would have to be done for a transmission in a 4x4 to work in my c20? You will need a hydraulic clutch setup. bell housing, flywheel, pressure plate/clutch and appropriate hydraulic slave cylinder for the make/year of the transmission. For a 2wd C20, the 4x4 transmission will need a 2wd tailshaft, tail housing and driveshaft yoke. The cab floor hump may need modification, transmission crossmember will likely need to be moved, the driveshaft will likely need to be modified in length.

As there were Dodge and GM versions of the NV4500 and differences between the Dodge and GM transmissions and between year model transmission, there will be differences in what you need to adapt the transmission into your truck.   

My $0.02, if you want to go with a NV4500 and keep the C20 as a 2wd, find a 2wd transmission and bell housing and go from there.  The earliest GM trucks (93-94) will probably be the easier swap, but may be the most difficult to find. Going with a NV4500 will likely be much more expensive than just doing the relatively straight swap for a 4-speed SM465.

I'm sure some others while chime in on NV4500 swaps.

Here are some pretty good write-ups about the NV4500. 
http://www.novak-adapt.com/knowledge/nv4500.htm
http://www.advanceadapters.com/tech-vault/nv4500/

[popsthebuilder]

Thanks Jason. I read some parts of the link you left. In my case it is starting to seem as if the cons out weigh the pros for the nv4500. Definitely a lot more cost effective to go with the sm465. Would fourth on the sm465
do better than third on my th350 as far as mileage is concerned?

[Canadian 4X4]

put an A833OD in it was offered in chevs for a couple years in the 80's

[bake74]

put an A833OD in it was offered in chevs for a couple years in the 80's

     2wd versions are easier to find than 4wd.

[Jason S]

Thanks Jason. I read some parts of the link you left. In my case it is starting to seem as if the cons out weigh the pros for the nv4500. Definitely a lot more cost effective to go with the sm465. Would fourth on the sm465
do better than third on my th350 as far as mileage is concerned?

No problem. The NV4500 may not the cheapest swap, but it is generally a good heavy duty transmission that has overdrive.  Final gear ratios for the TH350 (3rd gear) and the SM465 (4th gear) would be 1.00:1 (no overdrive).  You might gain a little in mileage with the SM465 manual due to less slippage, but it wouldn't be a whole lot.

[Grey73]

You could also go with the SM 465 and an overdrive gear splitter. There are a few companies making them now and that may be the easiest swap to get you a standard trans. with an overdrive.