quick and easy (and yes ive done a search)

intake and exhaust valve sizes for the 280z head

thanks all   sb

They're in the Service Manual.  Engine Mechanical, Specifications.

Diameter

In   44 - 44.2 mm    or   1.732 - 1.740"

Ex  3 - 35.2 mm      or   1.378 - 1.386"

Edited September 6, 201610 yr by S30Driver
addition

i have a fsm and the haynes manual. the haynes had the 280 intake but not the exhaust (it also listed the early 240 exhaust as 35mm) and i couldnt find it in the fsm.

google found me every other kind of valve on a 280 but the valves in the head

thanks to you both   sb

SB I think you should ditch the Haynes and get a $20 How to Modify Your Datsun by Frank Honsowetz. The things you've been inquiring about lately are thoroughly covered in that, plus it's a good read about older racing setups.