how do you gut the air boxes on 89 tpi's and how do you get more airflow

 

Take the Y snorkel loose from over the air filters and from the MAF. Set the snorkel off to the side. Remove the air filters. Use 7mm socket or nut driver to remove four screws holding the water baffles down (4 srews under air filters). Cut out the remaining baffles under the air filters. Reassemble.

For more airflow some people run tubes from the bottom side of the air filter down to behind the grille (where the foglights are if you have them).

Also in your sig, you don't bore a 350 block to a 383. You stroke it, (along with an inconsequentiall .030 overbore)

Martin