GM used to be a great company that made great cars. Part of this greatness was the way GM once made cars that were literally made to be modified. A good example being my 1976 Pontiac Trans-Am. I am in the middle of transforming it from automatic to manual – and GM designed (and. manufactured) my car to be easy to transform.

Though it had an automatic transmission installed at the factory, GM made it much easier for me to install the manual transmission it could have come with from the factory by drilling the subframe to accommodate a manual car’s hardware mounting points, such as the Z bar bracket and the bracket for the clutch return spring. All I had to do was tap the existing holes, so as to be able to screw in the bolts that hold the brackets – which align exactly right, which is no small thing. If GM had not drilled the holes in the front subframe. I’d have had to very carefully establish the correct location and then drill (and tap) the necessary holes. This would have been a much more delicate operation; if I didn’t get it just right, the brackets would be misaligned and the geometry of the clutch linkage all screwed up.

But it’ll be as exactly correct as if the car left the factory with a manual.

Then there’s the 455 V8 engine in my Trans-Am. It originally came from another Pontiac and was not paired with an automatic. It bolted right up because it was designed to bolt right up. It was also drilled – and tapped – to accept a very crucial component, the stud that screws into the block that supports the Z bar. All I had to was screw in the part. The Z bar was thus easily and correctly installed.

The 455’s crank had also been factory drilled to accept a crucial part for this conversion – the pilot bearing. All I had to do was tap the new pilot bearing in. If GM hadn’t anticipated that someone might want to convert their vehicle from automatic to manual and only made manual cranks for factory-manual-equipped cars, I’d have had to take the engine apart to take the crank out, in order to take it to a machine shop to have to altered to be able to accept the necessary part.

The rear of the 455 – its bellhousing – accepts either the automatic or the manual – without any modification or adapter plate. Everything fits as if it were factory.

It gets better still.

Installing the all-important third pedal – the clutch pedal – is also made easy because GM left a guide for where the hole for the rod that goes in and out (operating the clutch) when you push down on the clutch pedal is supposed to go. There’s a black plastic trim plate just above the carpet with a slot – and that’s where you drill. The rest is as easy as pushing the rod through the hole and securing the other end to the Z bar with a snap clip.

There’s still a hole – for the shifter lever – that must be cut through the driveshaft tunnel but that is also just grunt work because it’s obvious where the hole needs to go and once you’ve cut it, there’s a factory-style hump that goes on top, to which the boot/trim bucket bolts. It’s not rocket science.

It would be much harder to do a similar conversion of a current GM vehicle because they are built to be exactly the way they left the assembly line and no other way. If the car originally came with an automatic, it has a computer that was designed to run with an automatic that will likely not work if you replace the automatic with a manual. You will probably need to change the computer – and maybe even the engine, since it was probably made with sensors designed to work with an automatic. In other words, if you wanted to convert a factory automatic car to a manual car, in all probability, it would be necessary to replace the entire drivetrain and the computer.

That gets into money.

Not that my conversion has been cheap. But it has been affordable. I was able to defray much of the cost – of the new clutch and pressure plate and bellhousing as well as most of the incidental hardware – by selling the automatic transmission to a guy who plans to install it in his Corvette.

Mark that. The transmission that was in my ’76 Pontiac – which was originally installed in an ’80s Buick – is going to be bolted in an earlier ’70s Corvette, behind a Chevy engine.

GM was great once. I wish it would be again.

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