I am gettin my car from the shop tomorrow (finally with the SC installed).

I already bought an eManage with Boomslang PnP, and RC650 injectors. I was planning on getting the 9psi pulley from Tech2 (not sure about the size). I only have a headgasket on my car, no headwork done and also stock diff. Is there a smaller pulley that i can run safely without the belt slipping and without the risk of damaging my engine??

If so, where can I get that pulley? Smallest at Tech2 is only 9psi...

 

With your 650 injectors I would suggest not going smaller than 4.5 inches or so. If you have 750s then you could go sub 4 inch. I'm running a 3.8inch that runs max impeller speed at 9300 rpm.