How are you trying to set valve lash at this point?
First and foremost confirm your firing order, there is almost zero chance that an untouched stone stock edelbrock wouldn't have fired right up and run fine. Love em or hate them, they do work.....
As for your valve lash, here is a post that I def stole then copied and pasted, I use it on anything with a smallesh cam and once the cam is broken in I will go back and use a cut open valve cover and do it the old fashioned way.
These are the 2 things I would look at, confirm firing order, reset valve lash, then drain oil, add a comp additive PN#159 and rottela 15/40
Then get it fired and back to 2500+rpm for a complete 20-25 min......then drain oil, replace filter, another comp additive and new oil and drive it.
" With the engine OFF and spark plugs removed so that you can rotate the engine with less effort.1. Get #1 piston to compression TDC, Cam gear at 12 o'clock crank gear at 12 o'clock.2. Adjust the intake valves on cylinders 1, 2, 5, & 7 by loosening the rocker nut until play is in the pushrod then just take the up and down play in the pushrod and tighten the rocker nut 90 degrees3. Adjust the exhaust valves on 1, 3, 4, & 8 in the same manner.4. Rotate crank 360 degrees to get cylinder #6 to compression TDC, Cam gear at 6 o'clock and crank gear at 12 o'clock.*5. Adjust the intake valves on 3, 4, 6, & 8 in mentioned manner6. Adjust the exhaust valves on 2, 5, 6, & 7Getting the '0' lash is the same as I posted originally. Use the "up and down" rather than "spinning" the pushrod. You will find it to be much more accurate."