Gasket and Engine questions

Anybody here ever change their own valve gaskets?

It's such a pain in the ass to change the right side, since the upper intake manifold hangs over, requiring removal.

Any horror stories?

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My '87 model is from the Canadian plant, and has the 302cid block.
I've been planning to do some performance upgrades on it.

From what I can gather, it looks like an identical block you'd find in
an '87 Mustang 302cid (excluding the exhaust, intake, and upper intake manifold configuration). Is this true?
So is this engine a Windsor or Cleveland?
How can I tell if it's an "HO" engine?

Within most parts manuals, they seem to classify the engine as:
289/302/351W. But there are 302C, 302W, and 302M.
What's the difference, and what is the type of 302 used within the Grand Marquis's?

It is possible to switch the Grand Marquis double belt, to a serpantine belt? Has anybody attempted to put a supercharger on a Grand Marquis block?

Anyhow, I aspire to keep the block all steel (no aluminim heads, even though there would be better airflow and horses), and build to between 280-375hp.

The job should cost (given I do it all myself) $5000 for parts (excluding supercharger). That also includes rebuilding the entire drivetrain (tranny, driveshaft, universal joint, and rear.

Fortunately the Ring gear is an 8.8 anyway.
Later

I asked around, read some manuals, and have come to the conclusion, that the 302cid 5.0L engine block used within Merc GM's are identical to those used in Mustangs of the same era.

The only differences are the A/C & Alternator is switched to opposite sides, and the exhaust-intake manifold-headers combo.

So if you want to max your engine, pick up a Ford Racing catalog at your local race shop, and get going.