So, I am looking at a 69 442 which now has a 455 installed...I would much rather prefer the original 400, but ....I am told the car has 3:73 gears, does that sound like it may be original? I don't want to get involved with a car that has been too radically changed up by who knows who....really just looking a daily driver. Would appreciate your thoughts on the engine and gearing. Thanks in advance!!

 

Was the car Canadian built? The only 3.73 I can find would be a 41:11 gear set and would have the code letters TN on the housing and would be a type "C" axle (rather than type "O"). You need to hear from someone else who is more familiar with the 1969 rear axles than I.

 

Ozzie, thanks for the reply. I dont know where the car was built...maybe the owner is incorrect as far as the 3.73 info? Thats the thing with cars that have been modified to the point you really have to do some investigation to know what you're buying...

 

Look under the car. Is it a 12 bolt Olds or a 12 bolt Chevy?

 

What I was going to say. If it's a 12-bolt Chevy rear, the car was most likely built in Canada. If it's a Type 'O' then it's an American car.

 

Rather than speculating, simply look at the VIN and the axle housing. The VIN will tell you where the car was built. The axle housing will tell you if it's a Type O or a Chevy axle. As noted, 3.73 gears were never available for the Type O axle, however they were available for a Chevy. Here are the standard and available ratios for each model and drivetrain.

 

Joe, Good scoop on gear ratios.

 

This will tell you what was under the car when it was built but many decades later there is no guarantee that the original diff is still in place.

LOOK UNDER THE CAR!

 

The data tag will say in large letters "Made in Canada", if built there, though as noted, after 50 years who knows whats been done. A lot of owners and sellers have no idea what's underneath, and will throw out a gear set that sounds good. Gotta get a closer look at the rear.

 

Good point - the engine has been replaced so who knows what else was. Now it all depends on whether the OP knows what to look for

 

Which is why I said this in the first line:

 

Joe, I'm sure Dave understands the significance of the VIN. He is correct that it will state where the car was built. BUT it doesn't mean the axle housing is the one the car came with. We all know that what a seller says may not be what the car actually has That's why I questioned whether the OP knows what to look for. Maybe if he posted a picture of the housing it would help solve the question.

 

One more time:

 

We get it Joe. That's why I suggested 2x now that maybe the OP doesn't know what to look for (as in physically understand what a C axle and O axle looks like) hence my comment that I'd like jayvee53 (OP) to weigh in on the conversation instead of us going back and forth on this.

 

First of all, I would like to sincerely thank everyone for the replies! The car is in Iowa, I'm in Wisconsin and haven't actually seen the car. I suspect the current owner isn't sure on the details on the car and might have guessed at the year ratio. I was really trying to avoid taking the time to go look at the car if it has morphed into something other than a what could be daily driver. Just the fact the original 400 is out of the car kind of turns me off as I am thinking its not what I am hoping to find. I confess my ignorance about what I should be looking for to identify the housing which is why I was reaching out here. Once again, thanks for all the comments. It has been my experience that "car people" are really helpful and willing to offer advice when asked. Your comments prove that!!

 

If you're actually considering purchasing the car, you really need to go see it. For use as a driver, I wouldn't worry too much about the absence of the original 400-G. In many ways you're actually better off with the 455.

As far as distinguishing one rear end from the other goes, both have 12 bolts securing the cover but the Type 'O' is smooth whereas the Chevy incorporates a ridged baffle that runs diagonally across the cover between the 10 o'clock and 3 o'clock positions.

 

javee53 - Ask the seller to provide the VIN and also pictures including the differential. I didn't see it listed on CL Iowa so it must be a private sale?
I do agree that a 455 isn't going to be a problem You realize that the 400 is a BBO also, right? The M40 transmission (aka TH400) was built to handle the torque of that engine.

 

Allen, I private messages you