The Knee Bone is Connected to The Leg Bone

Our day started 

by discussing an article regarding a now common Classic car upgrade; the installation of a contemporary overdrive (OD) transmission. This includes a 5 or 6 speed manual transmission or in the case of an automatic equipped car, one with more than 3 speeds and OD.

The Main Focal Point of Most People
Based on the vast array of articles, it is the installation process. But after excluding these points, our main thoughts were why people were completing the conversions and the results. Two obvious reasons are fuel efficiency and noise.
Anyone who has taken a long drive in a Classic aged vehicle will quickly note the combination of gear ratios (transmission and rear axle) were developed around the expectations of their time. At 28¢ a gallon for premium fuel and typical highway speeds of 55 MPH, a 4-speed equipped car with a rather common 3.73 rear gear ratio would cruise along at about 2,200 RPM. 

But at today's $3.00 a gallon fuel and more common 70 MPH highways, engine speed jumps to a noisy, almost 3,000 RPM, while an original fuel economy of about 18 or 19 MPG completely tanks to about 12 MPG. Here's a link to a calculator if you'd like to explore on your own.

What most people tend to rationalize is all of the rest of the car was designed to go only 55-60 MPH on nearly vacant roads. These cars were also designed to handle and stop assuming far lesser speeds while surrounded by cars with similar shortcomings. So yes, it's great to be able to keep up with modern traffic speeds and nearly double your fuel economy, but it opens the door for all types of disasters stemming from so many other inadequate components.

As an example, many modern cars will complete an endless series of 60-0 braking distance tests with measurements of about 120 ft. or less. Popular muscle cars of the '70's required 150-170 ft. or more to do the same and without the benefit of an ABS braking system. Handling issues were very similar. In the following examples, watch how bad things really were.

Where's All This Headed Garagistry?
We believe two main points. Both go back to the title of this article. But most importantly, you don't need to have a "giga-dollar" budget to upgrade these items. In most cases you can upgrade your suspension and brakes for less than the 5-speed conversion alone, especially if you can do the work yourself.

First, if you are going to make your Classic go faster, you need to make it stop faster too. That means even if it has factory disk brakes, they are woefully inadequate. We suggest updating the brakes with modern components. There are numerous choices here. Wilwood and Baer both make disk conversion kits for many types of Classics and as you've seen in the numerous Jay Leo Garage videos, they will work with owners to create a "kit" to fit even more Classics.

Second, if you want to drive your Classic in ways similar to your modern car, you'll need to address an inadequate suspension system. There are numerous kits available which were designed to address these points and most were developed for installation by owners with decent mechanical skills. 

Again, we're not hawking any particular system (no do we get paid to do so), but this is a great overview of the level of difficulty and the results. As with the above videos, we cut to the end when you hit play. To watch the full video, just click near the starting point and the whole video will play.
So to conclude this post, if you are going to begin doing upgrades to your Classic, keep in mind that upgrading one component does not overcome other shortcomings. I don't believe we have similar regulations in the US, but I recall many European countries require "cross-matching" components when performance upgrades are done. That means if you make the engine more powerful, you have to upgrade the suspension and brakes maybe tires and wheels, sometimes more.