running in new motor

I assume you have done the initial start up and 15-20min run in with all the checks?

If you have and had no real problems, i.e you dropped the oil and it looked good. Make sure your timing is ballpark, something like 12deg initial and 34-36 total. Ensure your carby is not flooding the engine, blowing black smoke and ruining your oil. Take the car and "load it up". 3rd gear runs up and down the rev range preferably up some mild inclination. Start small then add 1000rpm each time always listening and monitoring your gauges untill you finally reach redline. So 2500-4000, then 2500-5000, then 2500-6000, and so on. After that you are done. You can drop and change the oil for a final check if you wish.

I would also recomend using a light diesel grade engine oil on break in or permenantly if you wish.