intake gasket replacement questions

[nrt69]

Im running a edelbrock intake on a 360 and the heat crossover at the head blew the gasket out so i replaced the gaskets to get rid of the loud exhaust leak.
heres my questions:

the car now pops and backfires a lot on initial start and while warming up. once warmed up, it runs ok. why?

the edelbrock intake didn't have a functional heat crossover in it so i don't think that the issue.

I think the elec choke is working when i start the car as it will idle 1500 ish, but then after 10 seconds or so it drops off and wants to stall.

i marked the distributor and rotor and put it in the same way so I'm guessing that's not the issue. (MSD eCurve distro)

Would a gasket leak be a cause? when i put silicone at the front/rear of the engine, it didn't look like the intake compressed the silicone at all.
i put a thicker bead on than what i saw when i took it off.

[cdr]

check the firing order of the plug wires

[nrt69]

i don't think its the plug wires since i marked the cap and took pictures of the routing.

[AKcharger]

i don't think its the plug wires since i marked the cap and took pictures of the routing.

Lol, famous last words!  those plugs wires have given me grief more times than I can count, I wouldn't rule them out until your rechecked them at least 8 times

[nrt69]

i rechecked the wires. the only 2 that i could've got messed up i switched and it definitely wasn't correct.

I doubt i turned the distributor any but before i check that i wonder if it could be an air leak at the carb or the top of the intake?

one rubber nipple blocking a port on the carb is old and cracked. the other one behind the carb running a hose to the valve cover is also old/cracked. haven't had a chance to replace those yet tho...

[nrt69]

Replaced the caps on the carb and intake that didn't do anything.
Tried rotating the distro to bring rpms down some (800-900) and the car didn't backfire through the carb but it popped out the tailpipe and ran like shite.

[68CoronetRT]

Sounds like its time to verify the timing and set it properly.

[forphorty]

yep

[nrt69]

it was the timing.
I'm surprised how off it was after setting the distro back in place...