First off its a 65 350/325sbc, the car sat for about 2 years, just recently i started to try to get it back to working condition. After letting it sit i decide to take it out it ran decent for sitting for that long but i noticed a rough stutter at higher rpm's. At that time it had a quadrajet and points distributor nothing fancy. I cleaned the whole fuel system out filters, changed lines, rebuilt carb.. The sputter continued and got worse over time. So i figured to throw some new parts on it because i didn't know when anything was last serviced. I continued to throw parts on it in the order i list it and each time the problem stuck around.

Holley PART# 0-82651SA (650 street hp mechanical secondary)
Mallory Unilite 3748201
Msd Blaster 2 coil
Spark plugs I noticed that 2 of the plugs were gapped all the way down to the electrode if that makes sense.
Spark plug wires
Msd 6al have a newer msd that i could swap to test
Alternator (90 amps)
voltage regulator
Ballast resistor .8 oms
Mechanical fuel pump 8psi
fuel filter

To me it seems like i have replaced everything that could be causing a hiccup in the system. I went threw the whole fuel system and electrical as well i have check the timing plenty of times and even reset it a few time to tdc and problem still continues the voltage is good as well. Fuel seems good the carb is out of the box im assuming that it should run some what threw the rpms even if it were to struggle it could rise over mid 2000's.


VIDEO of problem Its not the best video but you might be able to make out the sound

Any help would be appreciated as well as shops that anyone has had experience with in the south Florida/Miami area. This is at my limit of knowledge and experience. Getting close to giving it to a shop or throwing in a new lsx myself.

 

Is the engine a 350 or the original 327?

​​​​​​​Doc

 

First off, triple check the firing order...there are subtle mistakes that can cause engines to seem OK but behave badly at certain RPMs. The Mallory Unilite is very susceptible to voltage spikes and interference - they sell a separate suppressor for that purpose.

Here is one on a '67 Chevelle..(red arrow)..

In addition you MUST use a stock ballast resistor with the Unilite and IIRC that should be 1.8 ohms for your car (not 0.8 ohms). Others will correct me if I got that wrong.. If your engine is not original then I'm not sure what is needed.

If that Holley has an electric choke try running a bit with the power lead unplugged..and tapped off.

Finally, I'd pull those same two plugs again and see if the gap has closed up...let us know what you find. There are several reasons this can occur.

 

It is a 350, the original is covered and sitting aside. I'm going to go back over the firing order and make sure that it is right. The thing is I'm not sure why the car over time slowly started to die I checked the compression and it's within spec also within 10% of each other so the bent spark plugs is a mystery to me. And even before i installed the Mallory I had a points and the problem still was there

 

If the piston is hitting the plug electrodes and closing them up -- that's your problem...you need to pull the plugs again from the suspect cylinders... It may require indexing the plugs, different plugs or other techniques to avoid this.

 

I'm going out on a limb. If you didn't install the plugs, or due to age/memory don't recall the installation, pull all of them and compare each in a line up side by side. If those two plugs are one heat range different, you may have found the problem. Dennis

 

The plugs that were bent down to the electrode I just happened to stumble by them I knocked a box off the shelf and there they were. Those plugs were pulled off the car a few months ago so I don't remember what cylinder they are from. The new ones I just pulled out and cleaned the other day are all fine and I'm not seeing any signs of the piston bottoming out on the plug. I'll pull them again and see if I see any differences in color

 

Do you have a heat riser valve on the right exhaust, just aft of the manifold? If so is it operating, i.e, opening when the car is at operating temp?

If not, then most of the exhaust from the right bank is forced through the intake cross over and out the left exhaust.

Also, check to make sure your mufflers have not fallen apart on the inside and you have no blockage.

 

Mufflers are fine I've tried straight pipes and a full system. And as for the heat riser i have tried straight pipe and a full system and the problem is still there. But currently I have the full system and no heat riser