I had the rear switched out in my 90 camaro [305 tbi, auto] The stock 2.73 rear died, so I found a 3.42 rear from an 84 camaro in a local yard.

Everything installed ok.

But I have the following problems:

1) Speedometer is way off: at 50 mph, my speedo says I'm going 60 mph [according to the construction zone MPH signs.... 8) ]

2) My cruise control quit working.

Any ideas on what I need to do to fix this mess?

 

you'll have to get a new speedometer wheel for your tranny output shaft. try www.yearone.com or www.summitracing.com