incorrect valve lash adjustment symptoms

[68firebird]

I have a small block chevy, It ran fine on saturday after I put the motor back together from putting new head gaskets on. I figured I'd adjust the valve lash since I pulled the rockers to replace the valve seals. tonight I tried doing the adjustments, and now it runs like dog ****, studders and shakes like a *******. would this be because I have the valves hung open? I've never tried to do the adjustment, and I heard it was easy, but I'm not thinking it was.

[oestek]

Sounds like either mis-adjusted valves, maybe a missing vacuum line, or both... what procedure did you use to adjust the valves?

[68firebird]

http://www.chevyhiperformance.com/techarticles/148_0303_setting_valves_info/

Used that, but instead of bumping the motor, we turned the crank with a ratchet. We must have done it incorrectly, although we think we followed it pretty good.