Installed by the Speed Merchant in San Jose. Work done in half a day. $430, cause I didn't remove it, I drove it in. Go ahead and criticize for paying extra. At least I'm comfortable knowing the whole installation is warrantied. I asked if the truck had been road tested in 4x4 and they said yes then pointed out a note the differential mechanic had put on the invoice, something like; "Warning, do not drive in 4x4 in the snow because this is like a locker differential, you'll just slide all over". Being a bit skeptical I tried it out when I got home. It is very tight. I won't try that again on dry pavement, but I'm sure it will be fine on loose soils. Calmini indicated that it could make some noise for a short time but I had none. I'll have to get down to Hollister as soon as possible to give it a good run.