Looking at the only image you have provided I can absolutely confirm that it is a GREEN ONE other than that I can only suggest that it may be a 6 cyl type.
A side profile image will confirm it.
With the Holden conversion. Has the radiator been moved forward and the front chassis cross-member been cut to clear the bottom of the radiator?
If NO, then your gearbox may have been moved back to the 6 cyl position, in which case you will have a 6 cyl firewall.
Diana
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