Hangar 9 P-51 Mustang 1.50 ARF Assembly Manual page 45

Step 3
Prepare the engine mount for installation by sliding
four 8-32 bolts and washers through the engine
mount. Position the plywood engine mount spacers
onto the bolts as shown.
Step 4
Install the engine mount.
Section 17A: Engine Installation (Saito 180GK)
Step 5
Install the spinner back plate and propeller. Position the
engine so there is between 1/16" and 1/8" gap between
the back plate and fuselage.
Step 6
Remove the spinner back plate and tighten the screws
holding the engine to the mount. An 11/32" socket
wrench will make this task a lot easier.
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