GM certainly did a bang up job making these cars as slow as they are, and an even better job in making sure they stay that way. I am in the process right now of installing these hooker supercomp shorties (p/n 2055) on my '88 L98 GTA. They're the smog legal versions with the AIR tubes and so forth. I have the driver's side manifold off and i'm getting there with the passenger side manifold (keeping the A/C and the AIR). Along with all the usual complications of installing headers on these cars, noticed that the header thats supposed to go on the driver's side has the bung for the oxygen sensor facing the other way (towards the firewall instead of the front of the car). I don't know how much of a problem that will be but i'm wondering whether they're suppose to be that way. ANother thing, just from looking down there it looks its going to be a tight fit (if it even is a fit) for the tube coming off the #8 cylinder and the heater box. I am wondering if anyone had to do any modification to the heater box for clearance.