Maybe a leaking fuel injector, fuel smell. Did you remove injectors and use new o-rings upon reinstall?

 

Okay so truck still smokes on star up and start up only if its been sitting for a fee hours...could this be valve seal?

 

Highly likely.

 

to do the valve seals does the plenum have to come back off?

 

No.

You will need to remove the valvecovers to get to the valves.

You can replace the valve seals without removing the heads.

You will need a adapter that puts compressed air in the cylinders to hold the valves up, and a overhead valve spring compressor. Essentially you put compressed air in the cylinders to hold the valves up so that they don't drop into the cylinder.

 

Gonna be doing valve seals this weekend hopefully that'll fix it