That's a rare mid year with those mile on it Larry......you should be using it a LOT more. My 66 was originally a 300hp as well. Great motor.
You've all seen my 62 that I've owned for 40 years but just to refresh.....base 250hp 327, 4 sp. borg warner T10, 4.11 gear, custom walnut steering wheel and matching shift knob on Hurst, New....interiour, paint, rebuilt trans, soft top added, hard top in storage, 68 vette rally wheels with 66 hubcaps. One of my babies....
When I got it driving through the Rockies (last shot), after I restored it, interiour, and how it looks today.