I swapped my gears last night to Toyota 4:88's from 4:10 with 30" tires. Best Upgrade that I could have done it has sooo much power now but Ever since the swap now my speedometer is saying that I am going 60 and I know for a fact that I am only going about 45. I understand that the Speedometer would not read correctly after the swap. My question is How can I fix this? Do I need to get bigger tires or can I have the Speedometer re-calibrated? Thanks in Advance.

 

The have things called speedo gears that your cable hooks into on the transfer case.

 

Probably won't find speedo gears for that great a correction. You can get a speedo recalibration box from a speedometer shop or on-line to fix the speedo. I ran one on my '85 while I had 5.29 gears and 33" tires.