First- that's a very cool and very nice car.
...and nor for reality-
There is an 11,000 mile original 68 340-s 11 second street legal drag car down here with full original interior.
Could be put back stock or street race day two pretty easy.
Been on CL for over four months at 16K.
IMO, yours would be worth more-
A- the original color- Turbine Bronze has been SUPER HOT for almost 10 years
B- all the same color, especially to Mopar guys.
C- I like the idea of dropping in a less expensive motor and dropping the price, plus you get to keep that high dollar motor you know like a lover.
For the past few years lots of nice cars have been moving in the 8-12K market.
Anything over that has to be nut and bolt, super, super, super nice, or a bit more rare and/or documented/original.
I'm actually kind puzzled about that 11,000 mile 11 second car.
16 is almost #3 money, and it's clearly a #2 car with potential to be 2+.
http://www.collectorcarmarket.com/collector-car/prices/1968-plymouth-barracuda-formula-s-value.html