Here is the problem!!! 

I used 3 timing lights to make sure this was right. For best vacuum I have to set initial timing to 30 which is 17" vacuum. Any point below that drops the vacuum to 15" and below. No amount of tweaking the carb will let me get up to 17" without the initial 30 degrees of timing.

One problem that I fixed was the mech advance was coming in waaaay too fast. I changed springs.

I know my harmonic balancer mark is accurate because I checked it when I had the heads off.

Any clue what's going on? Why would I need so much initial advance with vortec heads?

76x38493.7541319444

Well from watching the Voodoo and Set Timing threads this timing thing is starting to get complicated, which ever way you decide to time your motor your motor and distibutor are going to have to be in good working order, you are not going to have any luck with a timing light if your distributor is wore out, the same with the vac. method as far as the motor goes, and if you have both a motor and dist. problem, well do I need to go further, I can't remember ever timing a street 350 with a stock dist. at 18 degs initial, a race full mech setup maybe, has anyone else?

   Ken, as I start to understand the vac. method it seems to me what your doing by advancing the dist. till you reach your highest vac. reading is what you are really doing is cranking in a bunch of initial timing and then compensating for detonation by taking out some of the total advance out of the distributor with different bushings and then putting heavier springs on to slow down the advance,seems the hard way to go about it to get the same results as you would with a distributor machine and timing light, what do you say?   anips38493.9289236111

Joel, you are exactly right.  Now you got it.  And yes it is much more difficult.  The reason is that you can compensate for individual engines differences and be right on.  With out the dist in the car and on a machine, you can set it up and do a good job, but you are not compensating for slight, or major, engine variations. 

With known engine set ups, you can go with what have been proven in the past to work.  But if the engine build up varies, so will results.  The results may be slight, maybe more.  It's the difference between vary good, and perhaps great.  In some cases they will match, others not.  To do this ideally, you put the car on a dyno and do many many variations until it's right, but that could take days of testing and a lot of small tweaking.  In a perfect world that's what we would all do.

The question is, is the extra effort and work worth it?  That's something only the man and his machine can decide.

I talked extensively with some engine builders in Dallas that have been working with voodoos. They said for best results in a 350cid with a 268 voodoo you need a high rise intake (RPM), 180+ runner/high flow heads, minimum 10cr, 2400+ stall (plus exhaust, carb blah blah blah). I was also told I need so much initial advance (30) because the voodoo 268 is just too big for my setup.

The vendor I got the cam from is going to exchange it no charge for a 60102 262 voodoo and guarantees much better results.

Oh well, live and learn! I'm sure many will be happy with a 268. Mine did run great at 2800+ it was just trying to get there....