Quote Originally Posted by big_block
we have about 18 lbs vaccum on the intake manifold or so
thats good vac. all i'm saying is most of the time a conv. (will stall a motor, not just pull it down 2-300 extra rpm's) when its going bad. i've put in a lot of conv. be never for that reason. in park what is your rpm's and what is it at in gear? is the vac. steady?