I would get better push rods, stock bend pretty easy.

Go with Comp Cam, custom grind they will/should recommend you valve springs & retainers for there camshaft and springs.

S.B.C. valves fit right in your 6 head.

Yes, new guides, (bronze type),retainers, (seals, Viton soft seal) keepers. Don't use the old school Teflon seals.
All new & matching for your components.

Stock lift is somewhere about .375" lift? .550" lift is a bunch more than stock. .500-520" lift is max I would go.
Got any specs for a custom camshaft yet?

You poor dad, gonna get spanked by your 6 \:D

Glad your pops car runs good., What was the HP & torque again?

Don't forget the methanol injection! Need to save your cast pistons from detonation somehow.

Have fun.

12 port SDS EFI