My new engine is being built this week, just a standard rebuild. The guy rebuilding my engine told me the compression was pretty low. I have had a boost problem where i couldn't boost over 6-7psi, will the new engine fix this boost problem because of the good compression?

Also i would like to know what kind of power my car will make before tune and after tune. My mods are downpipe, catback, pettit intakes, pulley kit, 8lb flywheel and a pfc + commander. I want to know what my power will be before the tune because a few months after the rebuild i will be getting injectors and a fmic then a tune. I want to know both estimated hp numbers because a 300whp sti wants to race me and i want to know if i should wait for the tune or if my car is capable of taking it down before the tune. Thx alot guys any help is appreciated. -Eric