360 in a 75 Roadrunner

I had a Chrysler 5th Avenue a few years back with a E58 spec 360.
Car weighed 4100lbs.
It had a 2.94 rear gear in it.
I used a low gear 904 transmission (2:74 vs 2:45 low gear).
stock convertor.
It did have headers & fake cats on it.
But still had all the comfort items.
It ran 14.80's all day & had plenty of low end to break the tires loose.
Had a '73 T-Quad on it.
I would bet that your car has a 727 transmission in it. There is a 2:77 low gear available for it, but it is pricey.
The nice thing about the low gear in the transmission, it lets you maintain the cruising speeds that you have now.