[rescue] SS20, hypersparc 125 x 4 upgrade won't boot

[root]

I have unpgraded a working  sparc 20 running two 75 MHz supersparc CPUs 
to a four CPU configutation using 2  625 series Bridgepoint hypersparc 
125 MHz CPU modules with 1MB cache per CPU.  I followed the routine to 
the letter in the documentation provided, the original Bridgepoint 
instalation book.  The boot PROM was upgraded to v2.25R, system clock 
speed left set at the 40/50 jumper setting, and the diag-switch 
parameter on the boot prom set to false as instructed before the 
hardware swapped out.  The  boot PROM in my system is otherwise set at 
the default values. 

Solaris 8, current media kit edition, was installed on the system and 
working properly prior to the upgrade.

After attempting to reboot the new CPUs, the system monitor seemd to 
properly identify 4 x RT625 CPUs installed, Keyboard, system memory 
(448MB), and the network address.  It didnot give a tabular listing of 
the CPUs as it did previously when beginning the Solaris boot sequence, 
then reels of a long sequence of diagnostics and crashes to a blank 
(black) screen.  Shortly thereafter, the system monitor attempts a 
reboot and the whole process repeats in an endless loop of unsuccessful 
attempts to boot. 
It seems the change in system configuration is crashing the OS.  The 
original docs outline necessary kernel patches for earlier SunOS and 
Solaris 1.x, and various 2.x kernels.  Is there incompatibility with 
this system config and Solaris 8?   Do I need to reinstall the OS to 
detect and  operate with the 4 CPU configuration?  I Searched various 
sources and could find no documentation of compatibility issues.

Any help appreciated.

Steve