74 225 slant 6 options

Why new exhaust seats? Aren't they hardened in 1974? If they are still good, leave them alone. That will be money better spent somewhere else. The super six upgrade is a good one. Depending on how far you want to go, milling the head for an increase in compression is also a good idea.....IF you want to go that far.

Before "I" did any mods, I would make SURE what's there now is in top tune and running condition. Start with a compression test. No sense spending money on exterior bolt ons if the inside is worn out. Remove the PCV valve while running. Plug the PCV valve with your finger. Rev the engine gently and take not of how much blowby comes out of the valve cover. If it's a lot, you've got some worn rings. Measure the engine's vacuum signal with a gauge. It should be over 16 Hg...closer to 20. The higher, the better shape it's in. You don't want to spend a wad of dough on a wore out POS.

Slant 6 or not, the car is only original ONE TIME. Some may say it's not worth much, but if it's original, that's worth something. Slants get thrown in the ditch all the time so they are pretty cheap and plentiful. If you're concerned about the original engine, pull it out and find another slant to warm up. At least that way, you'll still have old faithful waiting in the wings.

Just food for thought. If you do decide to mod what's there, just make sure it's not worn slap the hell out as described above before you drop a lotta coin on it. Just my 2 cents.