Dunno offhand, but 73 was the first year of the newer "boxy" looking chevy truck. 72 was the last year that was the same chassis as a 67. "67-72". Ford also has the same year sked on their changes, although their change in 73 wasn't as radical as chevy....:/ It's quite possible it won't work being they came off different chassis styles, but don't hold me to it. I'm pretty sure the 73 has a different front end on it though. In some ways, anyway. It sure drives different. I've had examples of both... I wouldn't be surprised if 72 was the cutoff date for your parts. Probably not what you want to hear... MK