i just returned from a long trip (see other posting), and for the last 
2k miles or so the van has made heretofore unknown noises.

relevant info: 1700cc engine, recently rebuilt, bosch 009 dist, weber 
progressive carb, new muffler (bugpack), new points/condenser

it backfires on overrun--lots of small pops and crackles following one 
larger one.  i fixed the exhaust leak, and replaced the badly burnt 
points.  the dwell is set correctly, and i have done lots of 
experimentation with the timing (i know 32deg total adv at 3500rpm) from 
4deg after to 8deg before tdc.  it has had no effect.  suggestions?

it also makes a very worrying clattering noise at all times.  it worsens 
during accelleration, but is everpresent.  it sounds like a mechanical 
banging, but i cannot identify it.  it does not sound like pinging, but 
kinda like it.  this van did not have this noise at all for a long time; 
it is new.  sometimes at idle, it will quiet down, but only for short 
times, and as soon as i hit the gas, the noise returns.  any ideas?
i will try to describe it better if you guys need for me to do so.

well, thats it.

thanks in advance for any advice.

evan