Thunderbolts with 427’s were fairly serious contenders. Though not a hemi, Ford came up with the tunnel port heads. Put several Mopars up on the trailers early in NHRA not to mention racking up victories in Nascar.
The 427 FE Ford was basically the same family as the 390. I built quite a few Chrysler and Chevy big blocks but never had a Ford to play with except my 390 that came as a replacement for a 360 in a truck I bought, and a few small blocks. Those were the good old days! Now I piddle with keeping my old Buick running and an old 4.7 Dodge Ram, possibly the worst truck/engine combination they ever made.
I had a friend that raced a factory acid dipped Thunderbolt back in the late 60s in the Tallahassee area.