Hi Dazza 38. To put the record straight, The original F111's came with TF30-P103 engines. The F111G's came with TF30-P107 engines. When the USAF phased out their F111's, the RAAF were offered a number of TF30-P109 engines from theUSAF fleet of various model F111's. When viewed from a couple of metres away both the P103 and P109 engines with their Afterburners (AB), fitted, are banana shaped - with only a few degrees out of wack from the 'Core' Engine with the AB fitted, whereas the F111G (P107's) were more in-line between the 'Core' and AB. To enable the F111C (and RF111C's), and F111G's to have a more common engine type, they modified the P109 core engine aft turbine section to be exchanged easily to accept either a P109 AB or a P107 AB and called it the TF30-P108.
Cheers
Chrisso