Pcd on A2-5 spindle noses

[will1200]

Just got in a manual set Tru bison chuck. When I ordered the a2-5 back plate for it. It came with a 4 bolt pcd on it And only one bolt fits, The other 3 won’t align with other bolt holes. Are there 4 and 6 bolt a2-5 back plates? Bison dose not list 4 or 6 bolt on any of there a2-5 back plates descriptions, but the picture shows 4 or 6 for certain back plates.

 

[usolutions]

there is 3, 4, 6 variants

 

[will1200]

Thanks,

Bison seems to not make a set tru back plate for 6 bolt A series spindles. Dose anyone know of were I can get one or if it’s safe to modify the 4 bolt into 6 and have some bolt holes interfering with each other?