how do i get the stock boost gauge to work with a aftermarket air intake on my 88 quest

Not Mine:   http://houston.craigslist.org/cto/3235724204.html

I was pulling parts off my wrecked 89 quest. And I looked at the spare tire something did not look right.     http://i1097.photobucket.com/albums/g350/apate1973/cars%20stuff/spare_tire1.jpg

Hello again,   A guy on my local Honda board recently offered me an HKS Intake for $75.   Does this really increase performance? I was told that it actually is worse because it sucks in the warmer air in the bay. It seems like a really good deal, but it wouldn't be worth anything if it worsens my performance.   Thanks!   http://i107.photobucket.com/albums/m308/ikonwun/Mobile%20Uploads/IMG_3043.jpg