Worth it to build my 273?

My 273 Commando build on my '66 Barracuda Formula S:
- port & polished heads
- dual exhaust with h-pipe - V-Force mufflers, 2 1/2" pipes
- 600cfm Holley Double Pumper
- Lunati Cam .515 / .525
- stock ex. manifolds
- Edelbrock RPM intake
- 4.10 rear
- 8 3/4 sure grip 489 case
- running premium gas without additives!
- 205 / 70 / 14 BFG's all the way around
- factory 4 speed manual trans.
Never had it on the track but compared to other cars I've had it feels like a mid - high 13 car. I tach 3000 @ 50mph but I suck at racing a stick so someone with some skill like a friend of mine makes her feel like a flat 13 sec. car....Have over 10,000miles on this set up!...
I want headers but there's nothing out there for the 4 speed & power steering combo.