Team Chevelle banner
  • Hey everyone! Enter your ride HERE to be a part May's Ride of the Month Challenge!

Status
Not open for further replies.
1 - 8 of 8 Posts

·
Registered
Joined
·
40 Posts
Discussion Starter · #1 ·
I have a 70 396 with a TH400 and stock tires. My question is, what is my rear gear ratio. I think it's 331 but I don't know. Doin 60 I'm running 3,000 RPM. Any help is greatly appreciated.

-Jeremy

------------------
'70 Chevelle SS 396
Frame Off Restoration
 

·
Registered
Joined
·
226 Posts

·
Premium Member
Joined
·
3,438 Posts
probably are 3:31s, I run similar numbers with 24" diameter tires on SS rims and 3:31s.. I cant be sure of my speed as my speedo is off some, but I ran the numbers a while ago and believe they worked out to 60 or so at 3000.

------------------
Dave (NY)
70 chevelle ss396 conv
66 chevelle ss396 hdp/conv
72 chevelle
TC member #493
Never forget Earnhardt!
 

·
Registered
Joined
·
638 Posts
Vampyro - post your tire size and we could get a better answer for you. I've been going through this with my 3.73 rear. With my 14" rims and 25.6" tall tire I'm turning 3300 rpm at 60. I have a set of 15" rims and 29" tall tires that I mount for highway trips. With the taller tires it turns 2900 at 60mph.

If you're running the stock 14" rims and a low profile tire it's probably a 3.31 rear. You can jack up the rear and turn the tire one revolution while counting the revolutions of the driveshaft. If it turns about 3 & 1/3 times then it's definitely a 3.31 rear.

------------------
Bob Von Kaenel
70 SS 402ci TH400 (Yes, it's the dreaded Cranberry Red, and I like it!)

We've not been called upon to hold the fort, but rather, to storm the heights!
 

·
Premium Member
Joined
·
1,147 Posts
Hope I have this right. It takes two people. Put a chalk mark on your tire, try to reference the mark to something on the body, maybe one of the screws for the wheel moulding. While you rotate the tire one revolution have the other person count the number of revolutions that the u-joints turn(might want to mark the u-joint so you don't lose track of which one you're watching). This will get you pretty close.
 

·
Registered
Joined
·
40 Posts
Discussion Starter · #8 ·
Thanks for the help guys, I went out and turned those tires and sure enough, their 3.31s. You guys are great.

------------------
'70 Chevelle SS 396
Frame Off Restoration
 
1 - 8 of 8 Posts
Status
Not open for further replies.
Top