can i use a cold air intake from a mass air system on a speed density, if i put a piece of tubing where the mass air senser is supposed to go?

 

Sure, why not.

 

Mac has some for SD cars...

Mac Air Systems

I just thought I'd post this if you needed to buy something -- give you options...

But if you already have the piece, yup -- by all means you can put a spacer in there...

- Jeff