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1. Have a '68 442 4-speed convertible that my best buddy purchased brand new, drove for a few years, let sit for 30 years, and then gave to me. I've got it restored to very good driver quality, including installing Holley Sniper EFI on it, but want to install front disc brakes. The problem is, it has the 14" Torque Thrust wheels he put on it right after he got it, and so far the disc brake kits say they have to be 15" wheels to clear the calipers. Any suggestions?
2. When my buddy ordered the car, he was told that A/C was not available in a 4-speed convertible, and consequently it doesn't have A/C. Was A/C unavailable in the 4-speed convertible?
Reply to your question 2... The only things I've seen that would have prevented someone from ordering air conditioning would be rear axle ratio and some performance options. Axle ratios above the low 3s were not available with A/C.
Does the car have a high numerical rear end ratio? Is it a high-performance model?
I had a 1970 442 convertible for over 30 years. It had 4-speed and air conditioning with 3.23:1 axle ratio. I got a copy of the dealer bank-loan papers from Helen Earley. That copy confirmed the car was built with air conditioning.
If that availability was different in 1968, somone will correct me.
2. When my buddy ordered the car, he was told that A/C was not available in a 4-speed convertible, and consequently it doesn't have A/C. Was A/C unavailable in the 4-speed convertible?
Your buddy appears to be partially correct. Below is the 442 page out of the 1968 Olds Dealer Specs Book.
First off, I don't think the car being a convertible had anything to do with it.
Note option C60, Air Conditioner, was not available if any of options G88, G92, or M21 was also ordered. The first two are axle packages, but M21 is the close-ratio 4-speed. However, the option just above, M20, is the wide-ratio 4-speed, and apparently you could have gotten option M20 with air-conditioning as M20 is not mentioned in the Air Conditioner line. However, look at the M20 listing closely. "3.08, 3.23, or 3.42-to-1 (G92) axle ratio required." So if you ordered M20 with either of the first two axle ratios, you could also get air-conditioning. But if you ordered M20 with a 3.42 ratio, you could not also get air-conditioning.
This is just what VC455 says in his first sentence above.
So, in sum, it appears that you could get A/C with a 4-speed only if you got the wide-ratio 4-speed with the 3.08 or 3.23 gears. You could not get A/C if you ordered the wide-ratio 4-speed with 3.42 gears or if you ordered the close-ratio 4-speed.
Last edited by jaunty75; November 1st, 2018 at 07:51 PM.
The factory wheels were 14" for your car. If you go with a factory style setup it might fit just fine. Here's a link to a thread with lots of information on disc brake conversions. John
This comes up regularly. The aftermarket disc brake companies don't want to spend the time to educate their customers on the differences between 14" drum brake wheels and 14" disk brake wheels. Suffice to say that nearly every 67-72 A-body car that came from the factory with disk brakes also came with 14" wheels. If your Torq Thrust wheels were made anytime after 1970, they almost certainly will clear STOCK A-body disk brakes with the stock 10.75" rotors (most vendors round this up to 11"). In the photo below, note the difference in the backside contour between the 14" disk brake wheel on the left and the drum brake wheel on the right. The outboard face of both wheels is to the left.
How can I tell whether it's got an M-20 or M-21 in it? Also, how do I tell what differential gear ratio it has in it? By the way, thanks for the earlier replies.
I renew my questions to the 442 faithful: How do I tell whether I have an M-20 or M-21 transmission, and how do I tell which (numerically) differential I have in my car?
how do I tell which (numerically) differential I have in my car?
The surest way is to remove the diff cover and read the stamping on the edge of the ring gear. The number of teeth on the ring gear and the number of teeth on the pinion gear will be stamped there. Divide the ring gear tooth count by the pinion gear tooth count and that is the gear ratio.
I renew my questions to the 442 faithful: How do I tell whether I have an M-20 or M-21 transmission, and how do I tell which (numerically) differential I have in my car?
The information in this link will assist you in identifying your trans. Good Luck
November 1st, 2018, 04:21 PM
