The 9.8 K20 pistons have about a 2.5cc dish to them, which in the F23 puts you at 11:1. Factor in a tiny bit larger bore for your P2W, and you're around 11.1 compression. It's not a huge increase from 10.8, but good to be aware of.
I think you'll find as many have here that a cast manifold can be quite a restriction at levels above 300hp. Devin is using a tubular log manifold, but I think he may even realize the limitations of that design very soon as he tries to break the 400 mark. Unfortunately there's very few options for other manifolds on the F23, and even fewer if you're wanting to retain A/C. Russianred was working on an ebay brand F22B ramhorn manifold, but I don't know if he ever got it mocked up.
550cc is only going to be good for 350-375whp on pump gas, and that's at 100% duty cycle. You want to keep injector duty below 85% for optimal efficiency. 750cc should work well for 400-450whp, but you're going to want 1000cc if you're shooting for more.
I've got one of these, and while it's not a narrowband, don't expect to tune off of it very well. Most reputable tuners won't even touch AEM widebands.
Russianred had issues with boost blowing out the O-ring between the plenum and the adapter. When I bought the adapter from him, I had a groove machined into the adapter to hold the o-ring, similar to the groove that holds it on the IACV itself.
Which one are you looking at getting?
Do you know the year the dizzy is from? I'd compare the connectors to see if they match up, then head over to technet.ff-squad.com to compare pin-outs.
