HK Citation 12 to ESP P101

I was reading about the mosfet conversion of this amp. and documentation. I have some left over T03 Profusion lateral mosfets and was cconsidering converting a Citation to an ESP P101.
The HK 12 that I can access is in great cosmetic condition, but it has a blown channel with some scarring on the drive board. The power supply works fine deilvering about 40 +/- Volts per rail unloaded.
Just don't know if I can shoehorn the ESP driver boards into the area where the Citation borads are mounted.
Anyone know the physical dimensions of the HK boards?

Thanks, Bill