Auto to manual advice

[Tyler94w]

Just got a 84 k10 350,700R and I’m really wanting to swap it to manual and I’m looking for some advice on which route to go. Its pretty much mint condition at least to me and I’d like a nv4500 but don’t want to cut and hack a lot of stuff on a good truck. I guess what I’m trying to say if converting from auto to stick is it about the same amount of work going to a sm465 or a nv4500 from a 700R tcase is a 208 any advice is greatly appreciated!

 

[nvrenuf]

465 vs 4500 is basically the same work - you've got to cut a hole in the floor (placement depends on which trans), swap pedals, modify driveshafts and deal with the tcase.

Also, check Advance Adapters on this. Seems like they may offer a 10 to 27 spline adapter coupler which would allow you to use an '84 and older 465 your existing 208 with the correct adapter plate.

If not....

Your 208 will have a 27 spline input so you'll either need to swap inputs or get a different tcase. FIRST, you'll need to decide on the trans because the 465 was available with 10 and 32 spline outputs and the 4500 will have a 32 spline output. Once you decide on which trans then you can work on getting the appropriate tcase pieces.

 

[Dutch Rutter]

From everything I've read about this swap, the nv4500 doesent require the tcase to be relocated when taking the place of a 700r4. Highimpact.net sells a swap kit (including hydro clutch) for these trucks including a 32 tooth front input shaft for the np208. You do need to source your own brake pedal and clutch assembly.

With the nv4500 not needing the t case to be moved, it would be the easier swap. And having OD (assuming you need it) would be the more worthwhile swap. Biggest difference is the tunnel, some of the auto trucks came with a existing cut out for the sm465 but that hole is not in the correct position for the nv4500 so cutting is needed along with everything needed drilled out for the clutch assembly.

If you don't need OD then go with the sm465.

I'm pretty sure @SquareRoot did this swap or at least very close to it and can give a lot more of the fine details.

 

[nvrenuf]

The embossed floor templates are in '85+ trucks, they also have dimples on the firewall for drilling the clutch master cylinder bolt holes.

Here's a template (I stole off the net years ago) for the factory clutch master cylinder bolt pattern.

You must be registered for see images attach

 

[Snoots]

Get some of this:

You must be registered for see images attach

And, if you were ever in the Service; there will be swearing. If you haven't before, you soon will. Heck, you might even come up with some no one has ever heard/uttered before. Best of luck!

 

[Tyler94w]

465 vs 4500 is basically the same work - you've got to cut a hole in the floor (placement depends on which trans), swap pedals, modify driveshafts and deal with the tcase.

Also, check Advance Adapters on this. Seems like they may offer a 10 to 27 spline adapter coupler which would allow you to use an '84 and older 465 your existing 208 with the correct adapter plate.

If not....

Your 208 will have a 27 spline input so you'll either need to swap inputs or get a different tcase. FIRST, you'll need to decide on the trans because the 465 was available with 10 and 32 spline outputs and the 4500 will have a 32 spline output. Once you decide on which trans then you can work on getting the appropriate tcase

465 vs 4500 is basically the same work - you've got to cut a hole in the floor (placement depends on which trans), swap pedals, modify driveshafts and deal with the tcase.

Also, check Advance Adapters on this. Seems like they may offer a 10 to 27 spline adapter coupler which would allow you to use an '84 and older 465 your existing 208 with the correct adapter plate.

If not....

Your 208 will have a 27 spline input so you'll either need to swap inputs or get a different tcase. FIRST, you'll need to decide on the trans because the 465 was available with 10 and 32 spline outputs and the 4500 will have a 32 spline output. Once you decide on which trans then you can work on getting the appropriate tcase pieces.

Thank you for all the info especially the template I don’t know whether to go with mechanical linkage or hydro I know where a 76 is with a 3 speed on the column I could get the petal assembly and linkage out of I just don’t know if there the same from76 to 84 and it’s 5 hours away

 

[Tyler94w]

With the nv4500 not needing the t case to be moved, it would be the easier swap. And having OD (assuming you need it) would be the more worthwhile swap. Biggest difference is the tunnel, some of the auto trucks came with a existing cut out for the sm465 but that hole is not in the correct position for the nv4500 so cutting is needed along with everything needed drilled out for the clutch assembly.

If you don't need OD then go with the sm465.

I'm pretty sure @SquareRoot did this swap or at least very close to it and can give a lot more of the fine details.

thanks for the high impact site looks like there a one stop shop for this kind of thing. I really don’t need the OD but I’ve got a 4500 in another truck and if it’s the same length as the 700r I think I will do the 5 speed swap Just hope the transmission tunnel want require heavy modifications

 

[Tyler94w]

Get some of this:

You must be registered for see images attach

And, if you were ever in the Service; there will be swearing. If you haven't before, you soon will. Heck, you might even come up with some no one has ever heard/uttered before. Best of luck!

Thank you sir I might have to get something even a little stouter than that but it will be a while got to get all the parts together

 

[Dutch Rutter]

@Tyler94w with the pedal assembly I do believe they are the same throughout the years. Or at very least can be made to work. The trick is getting one for your power brakes with the correct clutch. If you end up getting a setup from a vacuum boosted truck with a mechanical clutch setup that is what you'll be using.

Make sure not to get a pedal setup from a truck with the hydro boosted brakes unless yours has that kind of setup or you are going to swap that entire setup into it.

I was lucky and snagged a pedal setup from a newer truck 87 or so I think.. its setup for a hydraulic clutch and the vacuum brakes. Got it on ebay, along with a tilt steering column from a manual trans truck. For the sake of simplicity and flexibility I'd recommend a hydraulic clutch over the mechanical but thats just my $.02.

Keeping the np208 also means you don't have to change the speedomoter gear setup at all.

As for the trans tunnel, I've heard the existing hole needs to be elongated towards the seat. Some trucks (like mine) the trans tunnel can actually be unbolted from the cab. So I'd end up grabbing a second one to modify and keep the stock one just in case.

 

[nujac]

I have a fairly still low mileage GM crate motor that once had the non lock up tb350 auto. With mud tires the wheels would spin just hitting the gas at 20 mph. Everything was good except the rpms where way to high at highway speeds and MPG was lucky to hit 10s. I replaced the auto with an NV4500/NP205. I now get 13 mpg at highway speeds and 15 to 16 if I keep it below 60 mpg. All is not good and I am wondering if I should of used the factory granny gear four speed I had in the barn. The gear spread from 1st-2nd-3rd is fine. However 3rd to 4th is too big of a ratio change. 5th gear I never use because it is too high and just clobbers the gas mpg. I am wondering if the automatic axle ratio is different for an automatic than a manual from the factory. If this is the case it may explain the driveability problems I am experiencing. The truck was way more fun to drive with the TH350 but I would rather have a truck to have a manual for towing. The cost to change axle ratio on a 4x4 truck is expensive. I wish I would have thought about axle ratios before performing the swap.