Throttle body spacer?

im looking for a throttle body spacer for a 1990 5.9l (the efi version) but i cant seem to find it anywhere, all i found was for the 92 and up (mulit port). I have one for a 96 5.2 but it doesn't fit :banghead:.

If not are there any other bolt on performance mods for this engine? I was thinking of boring the throttle body, the spacer however was mostly for the sound.
Author: trivium