I have a 340 that I recently was honed and reringed. I ran the engine before that and it ran fine with just a small miss that was due to one cylinders rings being no good. Well I honed it and reringed it and now it doesnt want to run right at all. The engine is exactly the same as it was before except I had the heads trued. Stock cam, edelbrock torker 2 intake and 600 cfm edelbrock carb. Running cheapy autozone headers. I started the engine up and it will sometimes idle okay without missing. If you rev it up to say 2000 rpm though it starts running rough and missing pretty bad. If you drive it will only rev to around 4000 rpm. Also its making noise up front and I dont know if its bad fuel causing that where its a high compression engine or if its lifters not doing right. So where should I start? Im about to pull my hair out with this engine.

I wonder if the abrasives from the honing and with dis-assembly/reassembly contamination, you wound up wiping out the cam?

A cam that has gone round would cause similar symptoms.

Actually though, could be lots of things, simple to horrible.

Could even be an intake vacuum-leak, timing issues, distributor problem, etc.

I do have a brand new cam for this engine but I was wanting to run it a while with the stock cam first until the engine was broken in some. If I knew that was the problem for sure Id replace the cam. How can I tell? Also I just thought that ive had the gas in their 6 months so is it possible the gas is bad? Ive had gas in cars for well over that and not had any issues with it but would bad gas make it act like that?

Take off the valve covers and rotate the engine and see if all the valves are moving up and down.
Also make sure that the 5 & 7 spark plug wires are not switched. Very easy to do being they are next to each other in both location and in the firing order.

you need to find someone who knows engines... this is way beyond your knowledge... good luck dan

Best Quote i've read on Moparts in a while: "how about we try to help the guy out and teach him something so he doesn't HAVE to go find someone else?

none of us were born knowing all about mopars, or engines, or..."

Well Said!

Okay I checked all the plug wires and they are in the correct places. I pulled the valve covers off and all of the rocker arms seem to be moving fine to me. I didnt have anything to check them with but I can if its recommended. Just by eyesight I couldnt tell that any were moving less distance than others. Oh yeah its hydraulic lifters. I do hear some noise in the engine I just havent located it. Ive been around plenty of engines with bad rod bearings and this doesnt sound anything like those. This miss is too random. Any other ideas?

When you pulled the pistons did you pull the crank or did you pull one cylinder at a time?

I pulled the crank.

Did you degree the cam in when you put it back together or use the "dot to dot" method?

I have seen cams off as far a 8 degrees using the "dot to dot" method.

Try retarding the initial timing back a few degrees and see if it gets better.I developed a miss at about 2000 rpm after replacing a timing chain on my 383.It would only run up to about 4000 max because of to much mech. advance.

I just lined the dots up. I figured since it was a stock cam it wouldnt matter but maybe I was wrong. And ive put the timing everywhere that itll run and it still misses.

[quoteI would start with a mechanical inspection of the engine. it's a 340? did those all come with solid cams? if it's a solid cam,

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No, they did not. Only the T/A engines. So in essence not many.

Its been converted to pretty much a stock electronic ignition setup. Ive tried different distributors and even bought a new one for it. Tried different coils. Bought a new Ignition control unit. Ive also gone through various sets of plugs. Something else maybe i missed?

I'd check rotor phasing then on a difficult case like this one go back to basics, a compression test, note idle vacuum(is it steady), secondary ign (plugs/wires/cap)

Back to the basics.Compression test and go from there.

The idle vacuum is about 18... bumps around some when it starts missing but not by a great deal. Comnpression test shows 130 on the lowest cylinder and 150 on the highest.