NICK9818

So I have a Chevy 350 in my 76 and decided to replace the intake manifold with an edelbrock air gap performer and the carb to an edelbrock 770 street avenger. As well as replaced the distributor with a Mallory HEI. And I haven't filled any of the holes on the intake with the appropriate fittings/ vacuum fittings(Im not to sure what to call them) besides the thermostat housing. I set my distributor on TDC and my rotor point to the number 1 cylinder. And when I go to start it the carb backfires and a hole on the bottom right side of the carb on the intake backfired to. And now I can't start it. What do I do?

Haggisbash

You need to hook up the vacuum fittings to the appropriate holes in the manifold or your fuel mixture will be too lean. You could block them temporarily just to get the engine started but don't use something that could get sucked into the engine!!

JimT

Backfiring is usually a sign of bad timing. Are you sure the distributor is installed correctly? You could be 180 degrees out, Just because you rotate the engine to the TDC mark doesn't mean you are firing during the compression stroke - could be the exhaust stroke!
Good luck

ggroller

SH-60B

Adjust the timing with your light, yougot it close enough to start, now dial it in. set it 8° to 12° BTDCwith dizzy vacuum disconnected and plugged. Plug it back in when done . Plug all unused vacuum sources

jnb5101

Read Lars' "How to install your distributor".