Big inlet, exhaust or both? Valves that is!

[Black Beaut]

Hey All,

I'm starting to think about getting my E88 head finished up, it's already shaved and ported but needs new valve guides, seals and inlet seat. So adding in bigger valves at the same time makes good sense.

I've been looking at the S/S ones from Arizona Z as these seem pretty good value. Inlet sizes are 46mm or 44mm, exhaust are 38mm or 35mm.

Now is there any engine building logic here that suggests I should say have a big inlet and regular exhaust ot a big exhaust ('cuse me) and a regular inlet or should I just get the two larger sizes?

The head will go on an F54 block bored +2mm so there shouldn't be any issues with valves bashing the cylinder walls right?

Thanks for any thoughts!

Cheers,

Rob

[Ed]

I would think that the guys over at Nissan did there homework when it came to choosing what combination of size intake/exhaust valves works the best (in a stock application). So I would go with large on both sides.