1990 Chev 3500 stick 454

[Lqqk2trade]

Bought a 1990 454 3500 two wheel drive flat bed dual wheels manual 4 speed. Trying to figure best way to go to get overdrive. Does anyone make a bolt on overdrive for the NV3500 transmission? Truck is immaculate, 75000 miles. Motor was ran dry on oil, someone forgot to put oil in after oil change. Shame, motor looked brand new inside except for the spun rod bearings. I found 96 454 roller cam, freshened it up, used throttle body and everything off old engine. Runs really good, but it turn way too many rpms on the interstate running 75 mph. Any suggestions. I heard nv4500 trans is weak. But probably would be a simpler way to go. Thoughts on which route to take?

Thanks!

 

[454C2500Longbed]

Bought a 1990 454 3500 two wheel drive flat bed dual wheels manual 4 speed. Trying to figure best way to go to get overdrive. Does anyone make a bolt on overdrive for the NV3500 transmission? Truck is immaculate, 75000 miles. Motor was ran dry on oil, someone forgot to put oil in after oil change. Shame, motor looked brand new inside except for the spun rod bearings. I found 96 454 roller cam, freshened it up, used throttle body and everything off old engine. Runs really good, but it turn way too many rpms on the interstate running 75 mph. Any suggestions. I heard nv4500 trans is weak. But probably would be a simpler way to go. Thoughts on which route to take?

Thanks!

The NV3500 is the light duty transmission with overdrive, comes in half tons. Who told you the NV4500 is weak? It is a very strong transmission. The NV3500 will not work behind a big block, NV4500 is the only one that'll work in your application.

 

[Rock Hard Concrete]

An nv3500 will bolt to a big block, but not recommended. An nv4500 will be your ticket to heavy duty overdrive.

Another option is gearing up since you only have 1 drive axle. You would essentially be losing a gear, might not be a big deal to you if your truck has ample torque for your uses. Depending on your area and parts availability, gearing up could be a bit cheaper. Your speedometer would be off, though.

 

[someotherguy]

Bought a 1990 454 3500 two wheel drive flat bed dual wheels manual 4 speed. Trying to figure best way to go to get overdrive. Does anyone make a bolt on overdrive for the NV3500 transmission? Truck is immaculate, 75000 miles. Motor was ran dry on oil, someone forgot to put oil in after oil change. Shame, motor looked brand new inside except for the spun rod bearings. I found 96 454 roller cam, freshened it up, used throttle body and everything off old engine. Runs really good, but it turn way too many rpms on the interstate running 75 mph. Any suggestions. I heard nv4500 trans is weak. But probably would be a simpler way to go. Thoughts on which route to take?

Thanks!

You've been listening to misinformed people. Your transmission (if original) is an SM465.

NV3500's are overdrive transmissions as others replied here. They're relatively weak (light duty.)

NV4500's are original equipment in 2500's (8 lug models, not 6 lug), 3500's, and 3500HD's. They're pretty sturdy.

Richard

 

[eddie046]

The NV3500 is the light duty transmission with overdrive, comes in half tons. Who told you the NV4500 is weak? It is a very strong transmission. The NV3500 will not work behind a big block, NV4500 is the only one that'll work in your application.

If someone wanted to make an absolutely bulletproof package I would recommend a NVG 5600 with an adaptor to mate it to the Big Block. There were the transmissions they used in Dodge 3/4 and 1 ton Cummins trucks. Cast iron case and very tough. I'm not sure if they were ever used by GM but they were great transmissions and were a 6 speed with a granny low and an overdrive.

 

[454C2500Longbed]

If someone wanted to make an absolutely bulletproof package I would recommend a NVG 5600 with an adaptor to mate it to the Big Block. There were the transmissions they used in Dodge 3/4 and 1 ton Cummins trucks. Cast iron case and very tough. I'm not sure if they were ever used by GM but they were great transmissions and were a 6 speed with a granny low and an overdrive.

I think most of us 8 Lug guys would love one but the $5k price tag for just a bare used trans is certainly a deterrent.

 

[CumminsFever]

The nv4500 does have it's weaknesses, but overall it is a very stout transmission. Respect it's synchronisers and lock the nut on for 5th gear, use the correct oil, and you will get about as many miles on the nv4500 as the engine will last.
The nv3500 will fit and work... for a short period of time. Please don't plague yourself with it.

 

[Cadillacmak]

Bought a 1990 454 3500 two wheel drive flat bed dual wheels manual 4 speed. Trying to figure best way to go to get overdrive. Does anyone make a bolt on overdrive for the NV3500 transmission? Truck is immaculate, 75000 miles. Motor was ran dry on oil, someone forgot to put oil in after oil change. Shame, motor looked brand new inside except for the spun rod bearings. I found 96 454 roller cam, freshened it up, used throttle body and everything off old engine. Runs really good, but it turn way too many rpms on the interstate running 75 mph. Any suggestions. I heard nv4500 trans is weak. But probably would be a simpler way to go. Thoughts on which route to take?

Thanks!

If you have the SM-465, here is the link you want. https://www.gearvendors.com/product/manual-4-speed-muncie-m-465/
I like the rock crusher!

 

[someotherguy]

The nv4500 does have it's weaknesses, but overall it is a very stout transmission. Respect it's synchronisers and lock the nut on for 5th gear, use the correct oil, and you will get about as many miles on the nv4500 as the engine will last.
The nv3500 will fit and work... for a short period of time. Please don't plague yourself with it.

I was under the impression the 5th gear locknut issue was only with the Dodge versions. Can't remember exactly where I learned that but I believe it was on a rebuilder's page where they addressed the weak points. Rockland's site, maybe?

Richard

 

[CumminsFever]

I was under the impression the 5th gear locknut issue was only with the Dodge versions. Can't remember exactly where I learned that but I believe it was on a rebuilder's page where they addressed the weak points. Rockland's site, maybe?

Richard

I had thought so too, until I had a chevy one back off on me. It is not as popular in the gas engine crowd, or even the 6.5 diesel. However, it can happen, and did happen on my personal truck (4bt cummins). I chose to tighten it and put a dab of weld on it.
The transmission had less than 100k miles behind a tbi 350 before I mated it to the 4bt.