just purchased my first lt1 powered 95 firebird formula a month ago and slowly learning the ins and outs. a couple questions im sure you pros can easily answer. first one is the speedometer is roughly 10mph (thats at 60mph per minnesota law, blah) the previous owner said it was due to a tranny mod but in nerwer vehicles i thought this would be a rearend item? 2nd is i noticed a "chip" mounted on the panel under the steering column which i have take a picture of attached. thanks!

 

havent a clue as to what the chip is.



your speedo can be corrected with a tune/tuner.

 

is it the rearend that has been swapped?

 

Rearend gears could of been changed an then did not tune it to make it right

 

could he have meant a transmission swap from auto to manual or vice versa?

they use different reluctor wheels

 

said the auto was rebuilt and a kit was put in it...

 

a shift kit wouldnt change the speedometer calibration. A different set of gears in the rear would make more sense. unless someone messed with the pcm. who knows. Its all a guess until you can get in there a verfiy yourself.

 

gear ratio again is drive shaft full rotation:tire full rotation correct?

 

correcto mundo

 

Gears or difference in tire size? (I can't imagine it being 10 MPH off from tires but who knows).

 

what about a tq converter, could that do it?

 

Perhaps the PCM was swapped to one with a different ratio or tire size.

 

No, it would not.

 

got the stock size tire on the car in the back? if ur up around a 27-28 it will be that far off