Timing Question
 

I installed my SAFC II and my 450's last week but know I am getting some knock at anything over about 40% thr. I know this is due to the fact that the ECU is seeing less air for a given RPM coming into the engine so it has more timing. What I want to know is how many degrees could I retard the disrtibutor safely. I know it will hurt low end performance but I am really not worried about that. I realize that I would only retard it enough to get rid of the knock but I don't want to retard it to an unsafe level. Just wondering what you guys would consider a safe level of retard on the timing? Thanks.

94 prelude Si with a JDM h23. I had the timing advanced quite a bit so I had alot of knock to begin with. I have put it back to what I am pretty sure is stock because I made little scratchs on the mount bolt were the stock mark was before I advanced it.