ive read through this thread-not word for word-but thoroughly enough. i did check quadratec's site to see if any cold air intakes were available...but they only are for 91 and later. im not sure what the difference was in 89-90. if he fabs his own "cold air intake" this should, in theory allow him to put on any cone filter at the end of it...not just K&N correct? as long as he knew the size of the opening correct?
lastly id like to touch on something that ive seen in multiple threads here-the issue of people pulling out their cold air intakes (be it K&N or other brands) to swap with the stock box when wheeling for fear of dirt/dust pulling past the filter: i run the AEM unit and ive gotten that filter pretty well covered (not caked mind you) in dirt-i pulled it off to clean it and when it was off i took a moist napkin and ran it inside the tube to see if it would show dirt....came up clean. and has every time ive cleaned it. this leads me to think that perhaps the overall amount of dirt/dust it would take to pull through these modern day filters would have to be massive-something to perhaps consider if you're wheeling through the dunes..but maybe not for any other terrain.
the TBI t/b is different and i believe thicker (larger diam where the adapter on top goes) and also if i remember correctly it has 3 screws that connect the elbow to the t/b (or something similar, but the elbow can be reused i would think).
you are correct about installing a cone filter, although in that case the intake air temperature will be higher since has passed the thru the rad, so for example if outside air is 70F and the one that passed thru the rad (at engine operating temp) is 100F you can potentially lose about 5HP so unless the cone is enclosed is better to have a high flow filter in the stock airbox and make sure to get cold air from in front of the rad. The cone filter will flow better however, so best case scenario would be an enclosed (or at least shielded) cone filter.
