How did you change the timing on a TC? A compression test would be a simple test to tell if the vales seating or not, if it's bent it won't seat. If the valve stuck, the piston could hit the valve and bend it.
If it is cam timing, Then yes you can bend a valve
If it is ignition timing then no.
What makes you say timing?
Did you just do some work to it?
Please give more info!
What kind of pushrods are you using. Did you cut the p/r's and replace with adjustable p/r's or did you remove the rocker boxes and rockers. Did you allow the lifters to bleed down.
kemo