[cpartridge]

Just getting my new motor 347 stroker, all sorted out and have been driving my 65 Fastback and it was running great. I fixed a header leak and all was well. Now the car fires right up but there is a slight vibration that is RPM related. It's worse or more noticable at lower RPM's; you can also "hear the vibration" in the exhaust if you know what I mean. I know there are alot of things that could cause an engine vibration but everything was good and I haven't changed anything. Any ideas would be greatly appreciated.

[cindys_sn95]

are you sure it not a MISS causing it to vibrate.

[cpartridge]

It absolutley could be a miss but it seems very regular. I pulled all the plugs, checked them and they all looked OK. I maded sure of plug wire connections and checked for any arcing. I know the carb. (Holley 600) is questionable but this doesn't act like a fuel problem, but what do I know.

[cindys_sn95]

start checking all ignition parts, cap ,rotor, wires, ect. what kind of ignition are you using?

[cpartridge]

I have a Pertronix dist. and an Accel coil (old but OK?) All wires appear OK and connections are good,

[429ragtop]

check motor and trans mounts, you WILL feel vibration if they are poly. Also, isolate by removing drive belts for alternator, power steering, etc (one at a time). Remove fan and or fan clutch. If these things do not find the problem, check the harmonic balancer to make sure it is correct and in good shape. Look at the moving parts while you rev the engine (pulleys etc)