Forget the Pontiac and do a Buick swap if you go that route. Less weight and more power from the Buick mill.

I'd go the 560 way.

Rebuilding the M117 can be an expensive way to go. The parts aren't all that bad but the hidden snags can mount up. Threads in the block are notorious for stripping, bolts in the manifold/head have a nasty habit of being corroded into one piece, etc. Nothing insurmountable, just added expenses which quickly add up.

Just my opinion of course.

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“Whatever story you're telling, it will be more interesting if, at the end you add, "and then everything burst into flames.”
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