To those who have installed the Fast-start glow system on a w123 5-cyl Diesel , replacing the loop type glow plugs with the pin-style ones–

I want to do this to our ’79 300D.

So you buy this kit, and for 5-cyl engines there is a separate set of instructions from the 4 cyl application that tells you that you need to buy yet another relay to make it work.
This gives rise to three questions—

1) Does this mean that none of the 4 cyl instructions apply at all? (that part about slitting the harness was strange)
2) Assuming I only need to refer to the 5 cyl instructions, Is there anything special about this extra Bosch relay, or can another one be substituted?
3) If I need this Bosch relay, who has it?

Thanks to all who can help-

__________________
Nate Stanley
(Currently Benzless)
1985 F-250 6.9l 170K
2009 SCION XB 36.5K
2003 LS430 78K
2012 Kubota B 2320