Inconsistent stumble or miss

[TheBeardedOne]

So I have a 74 with Howell TBI the PO installed. I have a miss or a stumble best way I know to describe it. I have new coil, spark plugs, ignition wires,points, and O2 sensor all with less than 50 miles or 3 hours run time. I had a bad alternator and upgrade to a 3g truck seemed to wake up after this. I drove it 2-3 times around 40 miles total when I noticed the issue. May have been there all alone but I don't that it was. I can hear it at idle in the exhausts notes it sounds like a thump or a dun dun it is inconsistent tho. Also it happens when accelerating. My next move was to install duraspark 'll but wanted to just go back and check to see if everything is hooked up correctly as it was mentioned in another post I had that it looked like my vacuum lines were not correct. So all that to ask if anyone has the Howell install manual they can text or email me pictures of. Thanks in advance.

 

[EPB72]

The Howell website has a lot of manuals just click support on the home page..You can also unplug your 3g alt and try without see if that makes a difference...

 

[TheBeardedOne]

Thank you EPB I was able to find the manual I needed, and I will try disconnecting the 3g
To see if that helps.

 

[Cortez]

I just fixed my similar issue...uneven idle, and backfire on acceleration which was caused by a bad spark plug gap. I know you indicated yours are new, and expect you probably checked the gaps when you installed. Double check your plug wires, are they custom made (cut and assembled by you) or an out of the box set, see that they are fully seated on each end. Could be something simple.