Plans for use: I'm not going to beat it up on a track or abuse it running quarter miles, and I'm sure not going to build it into a show car. Moving without pushing it would be a change. It won't be going on highways for any distances based on the gas mileage I can expect alone. It might be something to get into when I want to hear a loud engine and feel the G-forces as it chirps through the gears.
A sleeper? That isn't possible. My M3 is de-badged and has 325 mirrors and bumpers- that's a sleeper. This car has the endura front and I promise it will be loud with headers through turbo mufflers and out the back with 1971 GTO tips. I hope the last engine owner cammed it when he put the intake on- if he didn't I will stick in a spare cam I have laying around. No one is going to assume it will be slow. I already have all the GTO emblems and it is really just a small moral dilemma because I went through a purist phase where I hated "clones."
The 6X-? heads: I didn't know what you meant, so I popped over to this website: 6x Head ID
I looked for the number on the vertical boss. There wasn't one.
The springs: I lowered all of my BMW's for the past ten years. When I see the Pontiac right now it looks like it is up in the air. The springs on it are of unknown origin and are much thicker in diameter than stock springs. I picked up a set of Eibachs on ebay and I have not yet put them on. A friend and I are working from the bottom up on the car right now, so the springs will likely be in the next days' work (Sunday or Monday.) I don't know what to expect from them and was hoping if someone hated them they would warn me off. The car itself has A/C, but I doubt that matters too much in reality despite their being firmer factory springs available for ac cars. I live in AZ, the A/C is a must.
The 12-bolt: my mechanic friend was telling me that these are incredibly rare and he was shocked to see it. What do they cost now? He acted like he walked into fort knox when he layed under the car.
Instg8ter, what's a stage four?
Another question: I have seen the poly body bushings advertised forever. The current body bushings are original. Are these a worthwhile investment in cash and labor? Should I expect insane vibration if I ignore this?
I'm also trying to decide what to do about surface rust on the frame rails. Apparently I decided to brush undercoat on the underbody and I ignored the frame rails 20 years ago. Frame-off or sandblasting seem a bit extreme.