My 350 sounds like it is hitting on 7 cylinders... (75 GMC)

[bobby dee]

So, I have deducted that this is a problem that I am not going to fix without a significant amount of time invested in, and since I have another engine... I'm just going to pull this one and put the other one in. (I was intending to do that anyway.) No worth the troubleshooting effort a this point, as I have exhausted all of the reasonable, easy, simple, fast potential issues. I WILL be starting another discussion about my 350/350 swap though!! which commences in 9 days.

 

[bobby dee]

new discussion on my 350 swap here...
starting in 7 days.

https://ck5.com/forums/threads/newb...ps-advice-warnings.332045/page-2#post-3827980

 

[paratrooper307]

So, I have deducted that this is a problem that I am not going to fix without a significant amount of time invested in, and since I have another engine... I'm just going to pull this one and put the other one in. (I was intending to do that anyway.) No worth the troubleshooting effort a this point, as I have exhausted all of the reasonable, easy, simple, fast potential issues. I WILL be starting another discussion about my 350/350 swap though!! which commences in 9 days.

Sounds like using a cannon to kill a mosquito, but your choice. One thing that hasn't been mentioned is to check your new plug wires very carefully. I've had issues with wires cracked internally or a poor connection (not fully seated) on plug or distributor, and the symptom always manifests as a miss under load, which typically disappears at idle. Worth a quick examination if you haven't already done so. These days, I don't assume new parts aren't bad out of the box.