All 1969 Mopar cars had wiring issues, all of them
One of the main issues was the alternator feed wire going through the firewall bulkhead connector and the inner nuts getting loose on the amp gauge, loose = high resistance which results in meltdowns and fires
Clean the connectors, both sides, and both wiring harnesses and clean and tighten the amp meter connections. Use non conducting grease on the plug in connections to stop corrosion also
I wonder how my 335 HP 383 4 sped in my 1969 Dart GTS would do against your T/A
It is down on power a little(380 HP) due to me making it street and pump gas friendly for a friend I sold it to back in 2002 before moving up here to Oregon, he sold it back to me in 2007. I have another motor in the shop that would wake that rascal up a little,750+ HP on 92 octane pump swill
That would be a exercise in futility due to the little tires on the back of that car