To check timing just put wrench on crank bolt and turn til marks line up ( Your bolt is old style BTW) Idle issue and bad miss- could be intake issue- I paid 2700 for mine - and had to drive 2 hrs home- same issue- Drove OK but got worse quickly. My truck would buck/cough Esp if up above 50mph. i know it says intake was done -but are you 100% sure? My truck had 125k when I got it. I reluctanly tore down intake- And spent around 450 for all intake parts- truck runs great now. As for fuel Vacuum my truck does that too- esp when hot weather. no noise though- maybe you were hearing air trying to escape? Good luck! I do like my SR- but still don't feel as confident as my ol 1990 LS with 270k LOL! I had hard time believing that was the issue with mine. I was sure it was something else- Hopefully part off the Butterfly did not fall in...