Popping sound from exhaust at low speed....

[CudamanTom]

Lets find out what your timing is now?

What kind of cam you running?

I don't know what cam I have. I purchased it from someone that didn't have that info.

[jhaag]

Is this engine new to you? (sounds like it is) Has it done this since you have had it, or is it a new issue? Does it have a noticeable miss, or does it run smoothly? I would check compression as well. Someone mentioned a burned valve. I will throw in a flat lobe on the cam. Happened to me, same popping from the exhaust. 

[dodj]

could be an exhaust leak .....

I had popping in the exhaust from a crack in #3 cyl header tube. Fine at higher rpms, popping on decel and lower rpms.

[CudamanTom]

Is this engine new to you? (sounds like it is) Has it done this since you have had it, or is it a new issue? Does it have a noticeable miss, or does it run smoothly? I would check compression as well. Someone mentioned a burned valve. I will throw in a flat lobe on the cam. Happened to me, same popping from the exhaust. 

Yes, this engine is new to me. And this is the first time (well second time) I've ran it on the road. Same thing both times.
I'm not dismissing a burned valve or flat lobe but tryin to eliminate the easy stuff first. Would a burnt valve or flat lobe cause a random pop? It's not constant, just random.
And I thank you for your  .

[CudamanTom]

I had popping in the exhaust from a crack in #3 cyl header tube. Fine at higher rpms, popping on decel and lower rpms.

I will recheck my exhaust connections. I just installed the headers and motor but will recheck them.
My popping is in acceleration only (at take off), not deceleration (or slowing down in gear). But I'm running a 4 speed too so that cause different results maybe? 
Thanks,

[HP_Cuda]

Did you get a timing light on her yet?

I don't know what cam I have. I purchased it from someone that didn't have that info.

[Chryco Psycho]

Vacuum reading will give you a good idea what cam you have

[Strawdawg]

If the vacuum gauge needle is bouncing at say 1200 rpm, I would consider it a potential sign of a valve or lobe

[dodj]

I will recheck my exhaust connections. I just installed the headers and motor but will recheck them.
My popping is in acceleration only (at take off), not deceleration (or slowing down in gear). But I'm running a 4 speed too so that cause different results maybe? 
Thanks,

Mine's a 4 speed too. Sounds like not the same issue as i had.

[CudamanTom]

Thanks for the input guys.
I had a busy day yesterday with honey-do stuff (had to share some free time with the wife).
I'll check the timing and will pick up a vacuum gauge to see what I have.
I'll report back on my findings.

[dodj]

Just FYI, msd blaster coils are meant to be mounted vertically. Not recommended by msd for horizontal mounting. It has to do with oil covering the windings and heat dissipation.

[Chryco Psycho]

Most Mopar coils mount horizontally so the blaster is not the best choice , MSD does make the blaster vibration coil which is Ok horizontally or any angle .

[HP_Cuda]

Good thing I saved the upright mount.

 

[CudamanTom]

Okay,

Got me a vacuum gauge and distrib spring kit today. 

But something don't seem right (at least from all I've been reading on the net)
I have about 8in vacuum (pretty steady with very little constant bounce), but at 1000 rpm idle it's about 40 on the harmonic balancer.
When I bump to about 2500 to 300 rpm, the reading of off the chart on the balancer.
I made minor carb adjustments to get smooth idle (as smooth as I can get) and highest vacuum and adjusted the distrib to get the highest vacuum.
I also changed out the springs in the distrib (one small silver and one blue)
What the heck do I have going on? 

[HP_Cuda]

8" of vacuum seems a bit low unless you have a very lopey cam and your car has a rough idle.

Check for vacuum leaks (any lines coming or going from the carb, then you might have to check your intake gasket next). Your advance seems well at bit advanced to be running 40 at idle? You should be down somewhere near 16 at idle then allow your mechanical advance to take you up to 36.