When I drive my '65 Ods Delta 88 it turns 2500 rpm at 65 mph, it has the stock TH400 and stock rear end (I'm guessing they are highway gears). I thought that this was kind of a high RPM for the car to be running at or is it normal? I am just curious if at what rpm ou guys are running with 4:10's on the highway......

 

Can't help you with 4.10's but my 3.90's put me at 3200 at 65.

My first Olds had 2.56's...it took me a long time to get over
NOT cruising at 2000rpm.

 

Here's a calculator that will tell you what you have. Note: It won't work, unless you enter your tire diameter.

Note: If any reply does not include a tire diameter, it will also be useless.

Norm

 

I can;t help with a guesstimate of your rear ratio, but I have to say, 2500 RPM at 65 MPH doesn't sound too bad at all! I'll thinking my '65 Jetstar (3.23 gears) is closer to 3K at that speed (maybe 2800).

 

Maybe it is ok, I just assumed it would run at a lower RPM. Also don't know if this makes any sense, but when I stand on the gas pedal, the car shifts out of first gear at about 3500 RPM, by that time it is going about 35-40ish mph. Is it supposed to shift at that RPM?