Show Your Big Block A body!

hey guys...just bought a 25k miled 1970 Duster from my buddy (HemiMark) and I would like to put in a 440..you know,..street car/coffee getter..anyone with the pros and cons/experience of this install. I would like to use the Shumaker mounts/tri y headers....I kinda like the small (1 5/8)pipes, prefer no larger than 1 7/8...gotta love the torque/streetability. I've seen fit issues on the later mount kit,,, the 73 and up A bodies.. I would like to hear from the guys that have used the 70-71 6cyl K frame kit and tri y exhaust...thanks for your help

Mopar to ya'
Denny