What are the differences?? SN89, SN92, SN93, VR4??

[DSBLK93GT]

I am looking at getting a used ball drive blower and I am not sure what to look for or to stay away from. Mostly I am going with this kit for a period correct install on my 38k mile 88 LX.

[speedytang]

SN89-SN92 uses a different case which is the case I recommend. The later updated unit was the SN93 housing which changed to increase strength on the ball drive. The insides are really the same on the unit since the 60's. They all use the same parts for replacement. The VR4 is a racing unit which they increased the pressure on the transmission(Ball Drive) and increased the impeller to a 4" and uses a larger 4" intake and 3" discharge tube. You can also under the right engine specs build 14psi and the VR4 was used for Renegade racing and you can make crazy power. Any 'SN' unit can be converted to a VR4 by changing the parts listed.(Impeller, Rear Housing, Increase Ball Drive Pressure) This is a 1 hour conversion process.

[DSBLK93GT]

SN89-SN92 uses a different case which is the case I recommend. The later updated unit was the SN93 housing which changed to increase strength on the ball drive. The insides are really the same on the unit since the 60's. They all use the same parts for replacement. The VR4 is a racing unit which they increased the pressure on the transmission(Ball Drive) and increased the impeller to a 4" and uses a larger 4" intake and 3" discharge tube. You can also under the right engine specs build 14psi and the VR4 was used for Renegade racing and you can make crazy power. Any 'SN' unit can be converted to a VR4 by changing the parts listed.(Impeller, Rear Housing, Increase Ball Drive Pressure) This is a 1 hour conversion process.

I am watching a SN-93 complete kit on ebay right now. Is it worth buying or no do you think? The buyer said it came off a 93 Cobra he bought. He has good feedback. I have found alot of others for slae in forums but I am a little skeptical about buying since a friend of mine got ripped off pretty bad buying over the net a year or so ago. Thanks for the help.