Lemans vs. GTO Gear Ratios

[jpdog357]

Guys:

I have decided to have a new limited slip carrier put in my 1972 400 Lemans and am considering swapping out the gears at the same time.

I am looking for feedback on what ratios were stock on a GTO vs. my Lemans as I am not even sure what it has currently in the car.

I am considering waking up the ol' girl soon with a 4 barrel and manifold but won't be going beyond that for now.

Also, any feedback on what is a good all around streetable ratio as I won't be racing the car and at best would like some street-light fun but also take the car on long highway drives of 100 miles or more on occasion.

Thanks,

Jason

[engineer]

generally 3.73 or higher is too much gear for cruising unless you have overdrive. 3.42 or 3.55 are fun and 3.23 is a good compromise. Almost any ratio could be obtained in the early 70s until converters came in and emissions made gearing changes.

[super]

A 3:55 gear would have been available and would be a great gear ratio for your driving style. It would be a good cruising gear and would still help you with performance. Super all around gear ratio.

[Larry]

With gas at $3.00+ per gallon, gearing is worth considering. As Super said, 3.55 was a great "GTO ratio", but 3.23 is very common, and if you add a 2800-3000 stall converter you can make your automatic work like you just popped the clutch... only without breaking anything!

This proved to be a great combination on my '69 Lemans wagon.

[super]

The 3.23 ratio should be easy to obtain and would work good in your car. As Larry mentioned, a slight stall converter will wake up the car considerably.

A 3000 Doug Herbert converter in my heavy T/A was worth almost a 1/2-second with no other changes. The first time I took off it snapped my neck back. It was the first time I felt the real potential of my engine.

A 2800 to 3000 would work good for your purposes. The converter will work good at highway cruising, etc. With a 3.23 gear and the correct tire, you should be able to cruise down the highway 70 plus mph with no effort.

Good luck on your Pontiac. Please keep us posted. Sounds like a fun project.