Quote:The A12 engine makes the most HP at 4,500 to 6,000 RPM. So anything you can do to get the RPM up will improve performance. Of course at higher RPMs your engine will wear out faster. It is a trade-off you need to decide on (the alternative is a larger engine)

Here's what I have done, and would do again:
First, use extra gearing. This 1) gets the RPMs up during normal driving and 2) multiplies torque which is the accelerating force. So it's a double-whammy
* Replace the stock 3.70 gears with 4.11 gears from a wagon. If you buy a good used center section (diff head), it's cheap and easy to swap
* Replace current tall tyres with short, wide tyres. I bought 165/55R12s -- they not only cornered better, but increased the effective gear ratio to about 4.2. This combo allowed a 110 kph crusing speed no problems
* When accelerating, shift at 5,000 for maximum effect

Next step is to free up the breathing of the little A12. Twin carburetors are best, but on a budget a new Weber 32/36 carburetor ($400) or used Weber 32/36 (or Holley G100/5200) makes a huge difference at anything over 5000 RPM. Buy the linkage kit and adapter and it's easy-peasy

Also to improve performance:
* make sure the dwell is correct (49-51 degrees)
* total timing is 32 degrees
* Remove one of the distributor springs so advance occurs sooner
* check that the vacuum advance works. This increases power at low throttle openings