Robert I also had the 2 piece bumper 1974 also. Mine was a M4 and it had a whopping 197HP 350ci. The 454ci. has a screaming 270HP. One might note a slight sarcastic bent to these two previous sentences. Unfortunately it was reality. This was an era when the insurance companies forced manufacturers to lower their HP ratings and the smog emissions imposed robbed HP and of course we older members will recall the Middle East oil embargo occurring then. Odd-Even gas fueling days with lines at the pumps spilling out into the streets. I was fortunate since I had another car and a motorcycle, which was excluded from the Odd-Even fuel days. Plus one car plate ended in an even number and the other was odd. I would just drive the one where I didn’t wait in a very long line or ride the bike.