Long story short: Just dropped a rebuilt (30k on build) in the Maro..sent her off to get painted. On the way home I noticed some problems. Whenever I let off the gas, I get a small puff of smoke out the tail. The quicker I let off, the more the 'puff'. Under normal idle, no puff, no smoke. Ive also developed a nasty lifter knock. So, two questions.......

1) what causes the little puff on decel?
2) What would cause a lifter knock with solid lifters and is it related to number 1?

 

Hmm.. it almost sounds like the puffing is due to your valve seals being worn.. but if you claim there is only 30k on the rebuild, I really dunno..

 

I forgot to mention the engine sat for about 5 years before I installed it....which would account for dried up valve seals.

Now, for the knocking. What would cause knocking? Its pretty bad at idle, sounds like a hydraulic lifter that isnt bled up yet....(Im an old Mopar guy and used to hyd lifters...)

 

Ok so ya it's probably dried up valve seals. Common problem on Gen-1 SBC's. Especially after sitting for so long.

But the knocking.. you said in the first post, they are solid lifters. Now it sounds like you are saying hydrolic's?

 

oil getting through the valves after being burned up by the spark plug. Just an educated guess. Usually Italian and German cars do this on purpose. It serves as a benifit when its designed that way. If not it is a definate wear issue.