- stages dont matter, youre taking it to a shop. get the intake and exhaust ports ported, the bowls polished, and a GOOD valve job (stock is 3 angle).
- what cam are you running? if youre sticking with the xp then why are you even porting your heads? this will determine springs.
- viton seals
- larger valves are useless for you. youre not even remotely close to needing bigger valves, especially with only an xp.
- i would start with L32 heads just because of the slightly larger intake valves and they'll most likely be way more fresh.
