Amazon - airbox assembly
 

Wanted: 1970 122S B20 original Airbox assembly for twin SU carbs.

airbox
 

Are you meaning the plastic black type that takes one big flat filter ? In 2 parts held togetehr with spring clips .? I have one but i think its missing one clip

Yes, I'm looking for the black plastic box type for the SU carbs.

Where are you located?

I can't send private messages. Please email details to adamg8770@gmail.com.

If i can get hold of one of these I think i might be able to make a mould and then a glass fibre version, i would imagine the clips are not difficult to find or replicate. I could even make it so it runs a K&N flat filter ..does anybody have one to lend....no mad rush when ever its suits, a few photos would help as well.

Does drawing the cooler air via the grill outlet make a noticeable performance difference rather than drawing from the usual air filters on the carbs?

Simple answer is yes, the air in the engine compartment can be as much as 20 degrees higher than the outside as a lot of the air has come through the warm rad plus the warm air off the engine and exhaust manifold just below, and the carb close to the bulkhead can be sucking even warmer air in... so can put them slightly out of balance.
So an air-box with a nice cold air feed from the front of the car is always better.
I'm sure the people in Amazon Cars did a few measurments on this in the past.

Air box
 

I have sold two recently sorry don't have one about at the moment to lend out . On early cars they are just too long to clear the clutch master properly but perhaps you could modify your mould to compensate for this ,youd sell more that way.

Yes adjusting a mould is easy, I would also like it to take a K&N filter if i could as then you never need to replace it just clean it...