340camshaft with stock conveter?

Purple Shaft Hydraulic Camshaft & Lifter Kit•Chrysler 273, 318, 340, 360
•Advertised Duration: 268°/276°
•Centerline: 114°
•Lift: .429"/.444"
•RPM Range: Idle to 5800

More info on Mopar Performance P4452782AE
this is the cam I have, here is my drivetrain combination... built 318 302 heads, matching m/p springs ,,, 9.5:1 -9.8- etc.. compression... 3:55 gears, 28" tall tires.. a998? or a904? from 78-79 passenger car with hydraulic lock up for freeway rpm use... now, question... is the cam too much for the converter? will I need a stall converter.. runs awesome but at idle and in gear with foot on brake vacuum reading drops from 20" idle to 7-10" then car dies.. only in gear sitting still, fine driving... so I was thinking I might have to go back to the original a904 with a 2200 stall converter..? thoughts?