When I retired to Flagstaff, I could really feel the change in altitude on the car. I would guess I lost 25% of my power running my standard engine and twin carbs configuration. So I made some mods.

I put in new gearing in the differential which helped with top end speed and actually gave me a usable first gear. I rebuilt the head to include new larger valves and ported and polished it. Those made a big difference so I went the extra mile and installed a modern supercharger. That increases the HP by about 50% to 75-80 HP. That is actually a SLK supercharger in a case made to look old style.

The combination of all those changes allows me to run the mountains without down shifting and to cruise the Interstate in the right lane at a respectable 65 to 70. I do not drive it at night or on holiday weekends.

In the TR3, I took a somewhat different approach. Rebuilt the engine to include a performance CAM and replaced the SUs with DCOE. It also handles the mountains well now.

In the TR 6 I just rebuilt the carbs and adjusted the timing using a old style vacuum gauge method and that runs fine.

If you drive old cars you need to modify them to meet modern standards. This winter the TD is getting disk brakes on the front.

Joe