> Are there any TR3 owners on this forum running a mild street cam ?
I have in the past, although not now.
> The stock valve clearances are .010" for intake and .012" for
Not correct. Those clearances are only for early cars with the cast iron rocker
pedestals. Spec for your 59 is .010" both.
> Is there an optimum gap depending on the spec of the cam?
Yes. The cam maker normally specifies what clearance the cam is designed for;
and generally speaking (not always), "performance" cams take more lash than
> Could you run .016 for both intake and exhaust?
It's been a long time, but ISTR that was the spec on the "3/4 race" cam I got
from Bap-Geon many years ago.
> Would an exhaust header factor in to the clearance
Not really, but kind of ... it's an old racer's trick to change the valve lash
to get effectively more or less cam. But the difference is minor, and doing so
is apt to shorten valve train life.
=== This list supported in part by The Vintage Triumph Register