1994 speedometer calibrating

[AuroraGirl]

So I checked out a few threads in the search, they were not helpful. A friend has a c1500 with 3.08 axle ratio , his axle was bad and got a used one with warranty

He now has 3.23 ratio now, and he has a 5 speed if that mattered, and he is 2wd. I am trying to find what he needs to do to fix the speedometer reading, since it will be off. His DRAC/VSS Buffer under the dash in the passenger side (Right?) is the thing that needs modification or replacement? How to do that?

Then, the ABS has to be changed in the settings with a Tech 2 and a ALDL plug to be the right thing, right? or does the ABS use the buffered signal thus would be accurate

 

[AK49BWL]

If the DRAC is calibrated properly, everything will get the proper signals - cluster, cruise, and ABS. I know there's a post around here somewhere about modding the DRAC module but I'll have to look when I'm on my computer.

 

[AuroraGirl]

If the DRAC is calibrated properly, everything will get the proper signals - cluster, cruise, and ABS. I know there's a post around here somewhere about modding the DRAC module but I'll have to look when I'm on my computer.

So is the DRAC something that can be just swapped? The guy im helping is on the younger side and has little mechanical/car experience, and im not going to do it for them, so if gm had different part numbers for different ratios?
They should have made it user-changeable like the pSOM In the f-series

 

[AK49BWL]

I would ASSUME it's possible to hot swap one, there's no software calibration so theoretically if he has the DRAC from the 3.23 truck it should just work. Toss it in and see.

Oh and yes the DRAC module is kinda velcroed to the metal dash frame under the glove box.

 

[AuroraGirl]

I would ASSUME it's possible to hot swap one, there's no software calibration so theoretically if he has the DRAC from the 3.23 truck it should just work. Toss it in and see.

Oh and yes the DRAC module is kinda velcroed to the metal dash frame under the glove box.

Darn, he doesnt have a donor vehicle it came from a company that puts a warranty on a used part