Correct me if I'm wrong, but wasn't the the Thunderbolt Galaxy 500 on a Fairlane chassis with a 427 shoved in it? If I am wrong, I trust your judgement as I was only 4 years old then.
nope.. they were both thunderbolts, but two different cars.
i think some of the thrunderbolts not only came with the hi rise 427, but some came with a 427 SOHC that produced well over 600hp.