Speedo/Milage change from 2.73->3.73

I have a friend giving me a AWESOME deal on a rearend from a Firehawk with 3.73's because he is converting his car back to stock. We will be trading rear ends this Saturday. I was just wondering how off caliburation will my speedo and Milage be? I just got a nasty speeding ticket so I really can't swing the cash for a tune right now. Just curious. Thanks all. ;)

The speedo will be way off and gas mileage will be going down, too.

Your speedo will read 36.6% higher than actual speed, and your odometer will tack on 1,366 miles for every actual 1,000 miles driven. It will also throw off any PCM parameters that are "MPH" based.

When driving a true 40mph, your speedo will indicate almost 55mph, at a true 60mph your speedo will indicate 82mph, at a true 100mph your 115mph speedo will be pegged, because its trying to indicate 137mph.

PS - I don't think any Firehawk left SLP with a 2.73 rear :)

Your speedo will read 36.6% higher than actual speed, and your odometer will tack on 1,366 miles for every actual 1,000 miles driven. It will also throw off any PCM parameters that are "MPH" based.

When driving a true 40mph, your speedo will indicate almost 55mph, at a true 60mph your speedo will indicate 82mph, at a true 100mph your 115mph speedo will be pegged, because its trying to indicate 137mph.

PS - I don't think any Firehawk left SLP with a 2.73 rear :)

Your speedo will read 36.6% higher than actual speed, and your odometer will tack on 1,366 miles for every actual 1,000 miles driven. It will also throw off any PCM parameters that are "MPH" based.

When driving a true 40mph, your speedo will indicate almost 55mph, at a true 60mph your speedo will indicate 82mph, at a true 100mph your 115mph speedo will be pegged, because its trying to indicate 137mph.

PS - I don't think any Firehawk left SLP with a 2.73 rear :)

He actually has a Formula, but the rear is out of a Firehawk with 3.73's.

Thanks though. :D