What are my options for a stick? Is this a bad idea? Would i just destroy my rig?

Its actually a good idea because you will get more power to the wheels. There are a few options for transmissions. The SM465 is a 4spd with granny low and then theres the NV4500 5spd transmission which is a good choice if you do highway cruising. Petersen's 4 Wheel Offroad magazine did a 5spd swap into a 80s truck with a TH400 and a 6.2. Fairly easy since you can buy the whole pedal assembly with the clutch pedal. I'm planning to do the 5spd Swap sometime.

Either a SM465 or a NV4500 are a great option. I would go for the NV4500 if you can swing the extra cost. You'll definitely notice a difference in power to the wheels either way.

What's the stock 5 speed in a 350 equipped 1991 Chevy 1/2 ton? I'm guessing that if it can handle the 350, the 6.2L should be good behind it... Any input?

What's the stock 5 speed in a 350 equipped 1991 Chevy 1/2 ton? I'm guessing that if it can handle the 350, the 6.2L should be good behind it... Any input?

The stock 1/2 ton 5 speed trans is the NV3500. It was originally designed to be used with gas engines no bigger than 5.2 liter, but a few got used with certain 350 gassers. It is rated for a engine with a max. torque of 300 lb. ft. and a max. GVW of 7200 lbs. A 91 1/2 Chevy 350 gasser is rated at 300 lb. ft. of torque - so the trans. was maxed out with the 350. A C-code 6.2 is rated at 240 lb. ft. and a J-code around 248 lb. ft. NV3500 is not very rugged, but a good light-duty trans. Used in S10s up to 1/2 trucks with 350s. 350 gasser of that vintage has substantially more torque than a 6.2 diesel - so overpowering it with a 6.2 is not a problem.
There were also a few NV3500HDs made - and they are rated slightly higher at 340 lb. ft. max.

GM also used a four-speed manual overdrive NP833 in many 6.2 diesel pickup trucks, Blazers, and vans. It is rated for a max. torque of 270 lb. ft.

I'm running an NV3500 behind my 6.2. It's a decent transmission and I love the stick shift but I can't say that I'd recommend it for a truck that is going to do much towing (at least not heavy towing) or off roading. It's a relatively small transmission.

As far as the manual vs. auto goes I think you'd love a manual unless you do a lot of city driving (or just a lot of driving in general). I always wanted to convert my truck to a manual. I finally did it when my third 700R4 went out and I haven't looked back.

Just one thing... I'd recommend that you spend the extra money and get one with an overdrive. The more gears the better.

i have the 5-speed out of a 1995 1/2 ton chevy 4x4, it is a good tranny, and i havent had any problems yet, the swap was pretty straigt forward, but you have to get a 208 t-case from a pickup with a manual, it has 32 spline input whereas a 208 behind an auto is 28 spline input good luck with it!!

i have the 5-speed out of a 1995 1/2 ton chevy 4x4, it is a good tranny, and i havent had any problems yet, the swap was pretty straigt forward, but you have to get a 208 t-case from a pickup with a manual, it has 32 spline input whereas a 208 behind an auto is 28 spline input good luck with it!!

OEM with a New Process 208 or 241 has 27 splines with a TH350 or 700R4, and 32 splines with a TH400, 4L80E or a SM465. My point being that some factory auto setups match the NV3500.

OEM with a New Process 208 or 241 has 27 splines with a TH350 or 700R4, and 32 splines with a TH400, 4L80E or a SM465. My point being that some factory auto setups match the NV3500.


i did not know that, all i know is my 208 came from behind a np833 good info though!

i did not know that, all i know is my 208 came from behind a np833 good info though!

How many splines is the 208 that hooks to the NP833? I've always wondered. I've got two 6.2 diesel 4WD trucks with NP833s, but never had the trans. out of either of them, so I have no idea which spline-count is used.

How many splines is the 208 that hooks to the NP833? I've always wondered. I've got two 6.2 diesel 4WD trucks with NP833s, but never had the trans. out of either of them, so I have no idea which spline-count is used.

Its the 32 spline version, it was my understanding that the auto's used the 27 spline and the manuals had 32, but im not sure. the np833 is a funny looking little tranny, looks like a loaf of bread:rolleyes:

Its the 32 spline version, it was my understanding that the auto's used the 27 spline and the manuals had 32, but im not sure. the np833 is a funny looking little tranny, looks like a loaf of bread:rolleyes:

The differing spline counts is not based on auto versus manual, it's light-duty versus heavy-duty. That's why the light-duty setups have 27 splines when used with TH350s or 700R4s, and HD setups using 32 splines with TH400/475s, 4L80Es, and SM465s. That's why I've wondered about the NP833. It's a fairly light-duty trans - at least going by it's torque rating. When apart, it is built heavier than the later NV3500 - except for one weak point between input and output shaft.
So, I guess it seems the NP833 does not follow convention if it uses the HD 32 spline-count.

In regard to the NP833 design - looks to me to be pretty much the same format as all the older muscle-car four speeds with side-cover, separate shifter, etc. - looks very much like the Muncie M21 or Saginaw. One difference though - is the NP833 was available in aluminum or cast-iron. I have three - all with 6.2s and they are all cast-iron.

Here's a bizarre situation...I have an '85 C10 with an SM465 4spd (really, a 3spd with a granny gear low). I'm trying to sell it, but since it's rusty and in Florida with no A/C I'm having trouble getting $1000 for it. It has a newer (less than 10k miles) clutch and seals on the transmission, and it's been bolted behind a 305 gasser. My current '82 only has 34k miles and is in great shape. It's got a TH400.

Is it worth the effort? Even if the spline count matches, will I need to get a shorter/longer driveshaft for the SM465?

My only reasoning is I know the clutch is great and I'm getting hardly anything for the truck as a whole. Plus, I have the clutch pedal assembly and transmission cross member if necessary. The '85 has 150k miles on it...how much would it be to rebuild the SM465?

you can rebuild the sm465 for roughly 150 bucks yourself, but unless either the bearings are screaming at you or you drove it without oil i wouldnt worry about it. i think your going to need a longer drivehsaft because the sm465 is not long at all (but it is one heavy sob).