Hey all, the previous owner left me without an air filter. I just cleaned the carbs and working on building out the rest of the intake. What filtering system would you recommend? Common ones I'm seeing are:

Ramflo Air Cleaner

ITG Single Air Cleaner

ITG Dual Air Cleaner

K&N Air Cleaner

 

K&N Carburetor Air Filter Set

UNI Air Filter Set

 Stock Air Filter

Edited September 4, 20222 yr by nkopp

I like the original. You have all the hose connections already there. They are a little tricky getting the cover and filter in place but once you get the carbs adjusted right you won't need to remove anything for a long time. The filters are still available from Nissan too.

https://www.courtesyparts.com/oem-parts/nissan-air-filter-16546e3210

The stock air filter would be my first choice. 

The stock air filter housing checks all the boxes:

- Cold air supply to both carbs, well protected from the exhaust manifold heat

- Fittings for the carb overflow hoses and crankcase vent hoses

- Air horns to smooth the air flow into the carbs

- Efficient filter specifically designed for the carbs

I did the ITG dual and have air horns inside. Float bowl vents and valve cover vent attached similarly to the original but I did have to drill the back plate for the vent fittings.

According to the ZTherapy VHS tape, someone did independent flow testing of a number of intake/air horn combinations, and the stock air horns flowed the best.  Nissan got it right the first time, looks like.