Educate me on early A vs 67-76A
1] Same K member on 6 and 8
2] Rear springs are the same
3] No 727 they only came with 904 and yes the crossmember is the same for cable and linkage
4] Not sure if anyone make big block mounts or headers for the early a
5] 360 will take engine mount side of motor mount reworked if you have the skills or buy a kit from Shumaker. To put a 727 in you have to fold or modify the lip where the floor meets the firewall.
6] For my disc I got a set from a 67 to 72 Dart to keep the small bolt pattern.