90's Mega Block information?

[Beach Goat]

My 70 Charger has a 580" under the hood, built from a Mega Block. It was an aftermarket block made by Mopar in the 90's, based on the 440 architecture, but besides that I don't know much about it. Information is hard to dig up....can anyone point me to some articles or tech discussions about these things? Or does anyone have one and remember the details of their development, how much they cost new, how you bought it/found out about it?

 

[fbs63]

In the 90's the ran $2800 and up. There were casting issues with some. They are basically a beefed up siamese bore version of a Hemi or 440 block. Guys sell them for a good buck because they have not been available for a while.