Yeah it ll depends on where the restriction (if any) actually is, there might be plenty of headroom on the inlet side and it's the exhaust is restrictive, or it could be the other way round with there being plenty of headroom on the exhaust side and it's the inlet being restrictive............... but as you say if both are done then you cant go wrong! lol

All I really need to know is if it is the standard ports causing the lag or if it's something else?!