Differential and ratio

[NorwegianGT]

Gents,

I've learned where to get the good answers,so here we go again..

I have a -72 GT,Automatic,bought from the US and is now beeing completly refurbished. I am going to put a 2.2i engine in it, and by doing so I might do something with the differential.

1)Are there any differences between manual and aut.transmissions when it comes to ratio on the rear axle?

2)What is the ratio in the rear axle?

3)Would you recommend to change it?

4)Where can I get new parts to get a ratio who suits a 2.2i ?

Thanks for any inputs!

Frank

[opelnut10]

Your GT has a 3:44 ratio for both Automatic & Manual transmissions. It can be changed out depending upon what you desire from the car. I would run it as is to see if you wish to have quicker take off or turn less RPM's at highway speeds. The two other ratios other than the 3:44 that were readly available are the 3:67 and 3:18, and they were in Kadett B. Both of these housings will bolt under your car and you will need the 3:67 carrier to go to anything numericly higher to install the gear. You more than likely will find that the gear in your car now will put you in 3000-3200RPM area at 100KMH depending on tire size. The larger engine will give you more torque which will move the car better at low RPM's and still improve top speed also as a result of the increase in power. I have this engine in my GT and I run the 3:67 with an overdrive 5 speed transmission and slightly taller tires, at 100KPM (62.5MPH) I am turning around 2500RPM.