I just finished installing new stock heads on my 79 vette (due to a bolt going into coolant from manifold) and used same intake, repainted both heads and Intake. Put Carb on as it was, just sprayed down with 2+2 carb cleaner. All vacuum line put back as they were prior to removal. Used new gaskets, bolts, plugs, wires and placed distributor back in same position as it was before it came out (new distributor put it and was working normal prior to head removal). I tightened all bolts to specs for Chevy 350. I used the following specs for Valve lash:
ADJUSTMENT
1. Rotate crankshaft until mark on torsional damper aligns with center or "O" mark on timing tab, attached to crankcase front cover, and piston of No. 1 cylinder is at top dead center of compression stroke. This may be determined by placing fingers on the valves for No. 1 cylinder as timing mark on damper nears the "O" mark on front cover. If valves do not move, engine is in the No. 1 firing position. If valves move, the engine is in the No. 6 firing position and should be rotated an additional revolution. - 2v With valves in No. 1 firing position, adjust exhaust valves 1,3,4 and 8, and intake valves 1,2,5 and 7 as described in step 3.
3. Back out adjusting nut until lash is felt at pushrod, then turn adjusting nut inward until all lash is removed. When all lash has been removed, turn adjusting nut in additional one turn. Zero lash can be determined by rotating pushrod while turning and adjusting nut.
4. Rot&e crankshaft one revolution, until pointer "O" mark and torsional damper mark are aligned. With engine in this position, adjust exhaust valves 2, 5,6 and 7 and intake valves 3,4,6 and 8.
5. Install rocker arm covers, then start engine and check idle speed and ignition timing.

Car sputters , but will not start. If gas builds up in carb a small backfire will happen here and there. Also, I noticed a higher pitched sound when trying to turnover. I checked firing order via Chilton and all wires are correctly placed. Could the valves be to tight? Any help would be greatly appreciated.

 

I kind of had this same problem so I set the balancer to 8 degress before TDC and it started. Also check that the #1 post on the distributor is pointing at the #1 spark plug wire.
I hope this helps.

 

I wouldn't be surprised if you've lashed the valves too tight. One full turn after zero lash may be too much. I spin the push rod between my thumb and forefinger while tightening the rocker nut until the pushrod stops turning. At that point, I go 1/4 turn (90 degrees) further on the rocker nut.

You may have to relash the valves after run up, but that ought to get you in the ball park.

 

It's either timing off a tooth or the valves aren't adjusted.