Clothes don't completely dry

Gas dyer. Heat comes on when you start it but at finish of cycle cloths aren’t completely dry and aren’t warm. Replaced the vent tube and dryer cycling thermostat. Same results. Bought a high limit thermostat but didn’t install it because it looked completely different than original ( part # 279048). Any help appreciated.

when it stops heating watch the ignitor, if it glows then shuts off without igniting the gas. you probably have a bad gas coil. they come as a set

Thanks, I went ahead and ordered a kit today.