85 1 Ton ?

[vbm]

Hello everyone. I don't post much but I do read the forums from time to time. My truck is an 85 silverado 1 ton with a 454, turbo 400, 14 bolt rear end and a dana 60 front diff. I don't drive it often but I do fire it up 2 or 3 times a week to keep everything working right. Well tonight I cranked it up and was letting it warm up and after awhile it started to miss and smoke started to come out of the left exhaust pipe. Is it possible that I sucked a valve just idling? Anyone have any idea what happened? I could sure use some help. Thanks.