Magnacharger

It is a 408 stroker I'll be in my Cadillac CTS-V. Is the high compression of 93 octane. with Magnacharge 112 with 4 lbs of boost

I'm not sure we

Generally with a compressor you would lower compression. Without supercharging you could go out with 93 octane and 10.8cr if you use aluminum heads. I think you'll be in trouble with the compressor.

** And if I put aluminum joints to reduce compression? **

You will not be able to drop enough by simply adding the joints, and anyway not a good way to lower compression first. You will be sacrificed to appease a lower ratio so you will probably have more problems. The good way is to use a domed piston. You need to talk to someone who knows their sh * t on supercharged engines. I've never built one, but generally they run much lower compression, as 8:1. Your camera is a factor too. I like talking to the guy Kieth tech black. It would probably be a good place to start. (800) 648-7970 aluminum heads may take about 0.5 essentially out of your CR because of better cooling overhead cast. (You run in 10.8, but it's the equivalent of 10.3 running with iron)

Your a lot of trouble running this boost to this compression. I saw the lands of pistons crashed because of it. I would check with the manufacturer of your compressor for their recommendations.

You'll need to boost octane or move your calendar to the point of power loss.