Trans-Am info for the 1966 Barracuda
Here is what little I know:
Sadly, Scott Harvey is dead.
The engines they ran were built 273's, as rules did not allow for de-strokeing, and the block's didn't allow for an over bore to reach the 5 liter limit.
A 273, built to "D" Dart specs would be a good starting point, with the application of "peroid" hot rodding.
One of the Team Starfish cars ended up with a gentleman who's last name is Martin; he wrote a book on how to make Mopars handle, published by SA Designs, now out of print. A friend has/had a copy, I will check. He raced it in GT 1 category for a while, then went back to vintage Trans-Am (I think). No idea where he or the car is.
From what I've seen (I'm 45 minuits from Watkins Glenn Internationl Race way) when I go up for Vintiage week end, there seems to be a semi loose interpertation of "peroid" correct, ie Camaro's with NEW Bowtie blocks, Boss 302 Ford's with new Ford motorsport Boss blocks. To be sure, there are some cars still with honest peroid equipment.
Go for every loop hole you can find and use them!!!!!!
Bob Tulius of Group 44 fame race a 66 Dart, and even won the Riverside race in 67.
Hope this helps.