I finally got my 67 95% finished. I needed to time it, so I bought a craftsman dialback light and set it to 35* @ 3000 rpm- with the vaccum advance off and plugged. I've heard about problems w/ the msd box and the timing light, so I may get a balancer tape to be sure. I'm trying to fine tune my new carb but I wanted to make sure the timing was correct first. Should I back off the timing some until I have the carb tuned? Would less advance be better for the street? Thanks.

With high octane pump gas, you should be safe with whatever is optimum for your engine. Most chevy small blocks like 36*, give or take a degree. The more efficient your induction, and higher the compression, generally the less timing you need. When you set the timing so its just on the verge of AUDIBLE detonation, it could still very well be detonating. One way to really tell is with a fresh set of plugs, make some hard runs up a down the road, and pull them out, examine with a magifying glass, and look for tiny purple specks. Those are pieces of melted piston. Start with 35* and you should be fine. Have fun with the new toy!

Randy

Just my opinion but I'd shoot for 32-34 degs btdc total timing. You can always increase or decrease it by 2 deg increments and test it out. Don't rely on the seat-o-pants meter though. You might dial in 34 degs and find it feels stronger at one point in a run but time slips might show different and 32 could be quicker. Every build is slightly different, read your plugs and go from there to know your combos limits. Then test at the track for performance settings.

What he said...

When u find your faint ping (detonation) back off 3 deg. With higher octane/compression, a dyno or road test at those revs the chances are optimum advance could be another 1 to 5 deg below that.

Faint detonation will not in practice show on the plugs unless it has been run like that or a long time...even then may not show at all.