Timing

[JMF]

Can anyone tell me what the timing should be on a 68 with a 440 ?

Currently have a problem where it's backfiring when going above 3/4 throttle, or if I floor it from standstill it will backfire, any other ideas what it could be? Thanks

[myk]

It really depends on your setup.  Considering that none of these cars are "factory" anymore you can't really have a specification to go by; you have to tune it by ear.  I and a lot of other people here have somewhere between 15-25* initial timing, and 36* total timing, all in @ 2500 RPM or so.  Someone correct me if I'm off on those numbers.  But again, that's what worked for my engine; YMMV.  Where's your timing at now?  It's been a while since Ron and Neil helped me out with setting timing but I believe they recommended that you set it at your prefered initial, then continue advancing or retarding the timing, trying to get the highest RPM possible....or something like that...

[69wannabe]

Yeah, I would start at 14 btdc and go up from there and see if it gets better. Mine is actually at 15 btdc and it totals out around 34 or 35 degrees. What carb are you running and check your plugs to see if they may be fouled. May even be low fuel pressure at high rpm's. several different causes of backfire. Low timing is a cause too tho