I have this problem as well. My car HAD a 1965 Florida title and when I bought it and brought it to Mass I could have paid sales tax on an original '65 427 CSX (state wanted $17,000+ in sales tax) It's now titled as a 2005
My block is from a 1984 Ford truck (Crate engine from the engine factory) so "in theory" I only have to comply with 1984 emissions. Should be easy enough, right? Wrong! The date code on my trans is 2005 (a tremec 3650). In 1984, ford didn't have a truck with a 5 speed, so guess what. . . I don't pass.
Oh, and my rear end isn't from a '84 truck, and the gear ratios aren't the same as what what offered in an '84 truck, so guess what. . . I don't pass.
So here are my options as the rules are currently written. I can
1. keep my paperweight in the garage and listen to my wife complain about the pretty car that we can't drive
2. Pull the motor/trans/rear and rebuild my car with a donor motor/trans/rear and look at the pretty paperweight with 2000 miles on it, perhaps selling it t a huge loss
3. sell the car to someone out of state, because I can't sell it here, and it's value has decreased, because the state changed the title from 1965 to a 2005 so my market is smaller
4. Drive with this
and everytime you're out risk a ticket/tow/arrest
The law changed in October 2008, cars that were already in the state at that time were grandfathered
BUT they can't sell them, because the grandfathering doesn't transfer to a new owner. So, a new owner would be in the same situation as me
Those of you that have suggested registering the car in another state, we have this awesome website in this state
http://www.mass.gov/rmv/forms/21760.pdf
It's a whistle-blower form, so that the old lady who lives next door/ or the guy down the street that's pissed at your kids can turn you in for not paying your excise tax in the state. They get money for turning you in!!!
awesome isn't it?