Jeep Strokers

I'm new to the site so Id thought Id share my plans and what I've got so far. Feel free to tell me what I did wrong or what I should change. I did allot of research before I started just wish Id come across this site sooner! Anyhow I've got 4.2 block and crank with a comp cams extreme 4x4 cam exact numbers can't be pulled from my head at the moment. I was guided by the tech guy at summit with info of what I intend to do. I also have a hesco aluminum head, newer 99+ intake complete with injectors and fuel rail and throttle body. Was considering having the tb bored vs buying a larger one. Rolland sharp roller rockers which I feel may have been a waste after reading some info on rockers on here. Haven't purchased piston's, timing set, or allot of the electrical components yet. I'm kinda bouncing back and forth between the tub and engine right now. Building my dream jeep from the ground up. Anyhow I went with the 4.2 block and 4.0 head due to price and availability. I was told the aluminum head would allow to run 87octane while running fuel injection on the 4.2. I was looking at keith black piston's there are two to choose from UEM-2227-STD and UEM-2226-STD these are through summit. I was leaning towards the second ones for the increased CR but am not sure how much gain I'd get or if it would hurt me on octane I'd be able to run. So that's where I am at currently any suggestions or experience would be greatly appreciated. This is my 1st engine build and hope to run this jeep for a long time. And if your wondering what I intend to run this with it's going to connect to an ax15 with an atlas II and probably 4.88 or 5.11 gears to run 37's. When it's all done.