I have built up a crate ZZ502 witha few mods for my 1967 Nova. Drove it 30 miles with regular dinosaur oil, changed oil and filter. Put in new dinosaur oil again and now have 100 miles on it.
When do you think that I can switch to synthic oil? I would have no problem changing it at 100 miles?

Opinions???

This is a street car not race.

Thanks