So I started this thread because I'm looking for advise for building my motor for 13:5:1 compression. My current setup right now is a gsr block bored to 83mm stock sleaves. Golden eagle crank, golden eagle rods, 11:0:1 JE forged pistons, ARP connecting studs, head studs ect. The head is a gsr head ported and polished with stock size forged valves, bronze valve guides, sk2 valve springs, sk2 titanium retainers, ect. Basically the head is totally fresh and built to flow air. I have sk2 pro 2 cams with sk2 cam gears, composite fuel rail, sk2 I/M with 68mm t/b. Stock injectors, sk2 2 3/4 exhaust from header back with no cat. For tuning I have aem ems v1 with the wide band air fuel kit. Basically I want to know from someone experienced what it takes to run 13:5, obviously high octane fuel bigger fuel injectors ect but I want specifics like are my cams gonna do good with that number, what octane fuel I should be looking at running stuff like that. I hope all my info will help with you giving me good feed back. If you have any questions feel free to ask