The car is of an age and with so many miles, I don't think the different engine materially changes its value.
If anything, the larger engine might be seen as a good thing, especially if it runs good.
What about your Firebird? Does it have a different engine, too?
Why are you asking? Are you finally going to take my advice and liquidate all of your cars that are in different states of disrepair so that you can buy a nice, used Mercedes????
:p
