I fitted an overdrive a few years ago and that’s been great. As u say it’s perfectly fine around lanes and back roads I was just wondering if there were any ways to give it a little more power for those hills and motorways?
Is it low end grunt you want or top end power?
Do you have a budget in mind?
The SU carb option will work well if your old carb is knackered. But will be more of a marginal improvement otherwise.
The 2.25p can be tuned, in the same way you'd tune any n/a petrol motor. ACR and others offer lots of bits, but price will wrack up quickly to do this. BTW - same is improved breathing, more air in and more air out. So head work, exhaust, intake and cam. Along with the right fuelling and spark control.
However ultimately you are limited by the nature and base design of the engine on how much more power you'll be able to make.
If you wanted to go wild you could probably adapt a turbo system or supercharger to the engine. But would require some R&D and cost.
Other options are a 2.5p from a Ninety. (which can also be modded).
Or some other kind of engine swap. Of which there are many choices. TDI's are popular, but noisy and unrefined. The 2.0 litre T-Series can be made to fit and would likely be a nice swap, but engines hard to find these days. And the ever popular Rover V8 swap, which is well known and works very well.
