A 5.4 is a modular engine, i.e. overhead cam. AFR heads are overhead valve, pushrod heads. NO WAY!!!
If you want to do a 5.4, build a custom 5.4 shortblock with good pistons and rods. Build it with 5.4 DOHC heads. See the modular section for 5.4 DOHC conversions. The 5.4 is huge too. As wide and tall as a 427 big block.
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