Welch plugs

[rickjen]

Hi all, I need someone to confirm the following b/4 I check myself into the mad house.
Originally got by mistake FB set brass plugs 3x wrong size-------did some research and found that 1 1/4 required for manifold side-------tracked down where to buy "thanks to the forum", received yesterday and went to install today.
Will not fit !!!!!!!!!!!!, measured with vernier calipers this time, (1  3/16in) will wait now till Monday to reorder again but cannot find any data on the net or in the documentation  I have that will confirm this.
FC Holden Grey Motor, L385970
3 x 1 3/16th
Thanks in advance
rick
PS: just finished putting block together,
New---- Bearings "Main and Big ends", rings, crankshaft / cam checked polished and balanced, gaskets, water pump, alloy cam gear, thermostat etc. Waiting on the head to come back.