have you thought about maybe going to a good dual puller electric fan setup ? your pusher fan may be blocking some airflow. just a thought from an old forgetful guy.
yes i have tried that , used an Aust Ford Falcon unit . Never had an issue till the World block , maybe a little worse again since having to fit the Jaf fan hub
Tex
New best ET 10.259@129.65 . New best MPH 130.32 Finally fitted a solid cam, stepped it up a bit more 3690lbs through the mufflers New World block 3780lbs 10.278@130.80 . Wowser 10.253@130.24 footbraking from 1500rpm Power by Tex's Automotive