When to switch from MSD#8207 to #8253

[dutchrunner]

Now have Blaster SS coil (8207) in RR.
572 Hemi , efi , 10:1 cr. max rpm 6200.

Called MSD tech but got no clear answer on when to switch from 8207 to 8253.

Any advice? Going on dyno 11th May.

#8207
Turns ratio: 70:1
Primary resistance: .355 OHMs
Secondary resistance: 4.4K OHMs
Inductance: 6.9 mH
Maximum voltage: 40,000 Volts
Peak current: 300 mA
Spark duration: 220 uS

#8253
Turns ratio: 100:1
Primary resistance: .16 OHMs
Secondary resistance: 630 OHMs
Inductance: 3.5 mH
Maximum voltage: 44,000 Volts
Peak current: 450 mA
Spark duration: 450 uS