Have got a 78 r200. How do I find rear ratio?

[Guest Anonymous]

Hello, have been reading this site now for a couple of weeks. Just decided to join in. Kinda feel like I know alot of you guys. My mechanic is installing my 93 Camaro v8 next week. I have a great t350.My car is a 78 280z. Would like to use it...but I am afraid of my rear end ratio being a 3.9 instead of a 3.54 or lower. How do I tell? I know the t350 will make the motor scream at 65 with a 3.9 ratio. Maybe I wont have to buy a 700overdrive if I have the 3.54 or lower. Thanks in advance. p.s. I do have a 79 280zx 2+2 parts car with a good rear end. Wonder what its ratio is? Thanks in advice. I tell ya, there is a site for everyone huh?

[John Scott]

Spin one axle (make sure the other remains still) 2 revolutions. Count the # of turns the pinion flange makes. 3 1/2 will be a 3.54. almost 4 will be a 3.90.

JS

[BLKMGK]

I'm not a Z expert but I THINK I've heard that the 2+2 cars actually had a LOWER ratio rear in them! This is due to it's heavier weight so before you consider swapping it in you'll want to check this out. ZCAR.COM would be a good place to search if no one else here knows for sure.

 

In the end I think you'll be happiest with an overdrive tranny - even a 3.54 will be making some noise at a 65mph cruise. Get it running with the trans you've got and then decide I suppose, I think the physical sizes of a T350 and a 700R4 are such that you might be able to use the same driveshaft with both but I'd double check to be sure if the cost of a driveshaft matters much to you.

[Scottie-GNZ]

Here is a URL all Z owners should bookmark.

 

Scottie

http://zhome.com/ZCMnL/tech/GearRatios.html

[Guest Anonymous]

Just for info, the t700 is longer than the t350 so the same driveshaft would not work.