hello, I have a 69 firebird convertible. Ive had it for 26 yrs. It has a 350 2bbl from a 72 Lemans I let it sit for a number of yrs and now Im trying to get it going again. I cant idle it down... Idle screw backed all the way out.I set the timing at 8 degrees btdc w/vacuum hose plugged.when I plug vac hose in it jumps up approx 10 degrees. does this sound right? Its going through gas like crazy.It almost seems like it has a huge vacuum leak but intake vacuum is 18 steady. any sugestions?? Thanks