3/8s NPT thermostat connection points - fan relay & water temp gauge

Well I have just drilled and tapped the intake on my LD340 on my duster, I found that thermostat spacer after I already drilled and tapped the intake.
I used the spacer on a LD4B on my old truck and it worked fine.
I also drilled and opened up a port on a mag M1 duel plane I had.
The spacer is easier.