[nUcLeArEnVoY]

Sucks that happened, man. Same thing happened to my car at some point. My '79 started life as a W72 T/A 6.6 car, but the original PWH block is long gone and was replaced at some point with a plain jane XA 500557 block from late '76. I was aggravated to find that out. Can only imagine what happened to the original block - must've been a severe failure, since it takes a lot to condemn a block. Oddly, the 6X-4 heads, correct carb, satin chrome valve covers, intake, exhaust manifolds, emissions, etc. are still on the car. Outwardly, the block itself is all that seems to be unoriginal, though I figure internals have been replaced.

I have a virgin standard bore 481988 PWH block that's been magnufluxed sitting in my sister's old room waiting for a future build, and if I could find that, you can easily find a YU 500557 block for your project. Those blocks aren't that desirable since the webbing in the saddle isn't as thick as the 481988 blocks, but if originality is all you care about, then that's to your benefit since people will give those blocks away like candy on Halloween. There are services out there that can punch in the numbers to match, too. I think Butler does it.