This post starts out as a nozzle thread, but if you read down, Anarkey's getting some impressive results using methanol, I wouldn't expect to run this much boost with stock syty heads, but even 23-24 would be impressive, especially with 20 degree mats.
http://www.turbobuick.com/forums/showthread.php?s=5800b8255ea0a5f3639ddba30745fa41&threadid=64202
http://www.turbobuick.com/forums/showthread.php?s=5800b8255ea0a5f3639ddba30745fa41&threadid=64202