hey man i'm going through a almost identical situation so i can relate and sympathise in that respect.
i'm 26 and married and i'm struggling heaps to finish my project coz of money and i've never had a problem with money ever before...the truth is that if i stop working on it i can live comfortably (sort of) so an option would be to just kick-back for a while and live your life and concentrate on making money for a few months...it sucks looking at it and aching to get out there and drive it but thems the brakes.
another option would be to part it out and sell the engine package and car and parts all seperately to make as much cash back as you can and restart the project whenever you're good and ready.
theres a problem with each of these above options...and thats the wife/fiance...in the first option you'll find that she'll complain a little (if not a lot) "that car has been a disaster to our lives" etc.
and similar with option 2 but this time she'll be happy that you're selling it off and getting rid of it for cash but when you ever say you're starting it again, all hell will most likely break loose.
at the end of the day you just gotta be responsible...there are many more important things in life than our cars (especially if you're planning a wedding and/or living on your own) that we have to think of before our cars and the women will always remind us of that but on the same token...we love it so much and feel empty without that being a part of our lives too.
i just realised i havn't helped you make a decision at allyou're damned if you do and you're damned if you don't but personally what i've done is give it a rest for a while until i get back on my feet (it happens to all of us from time to time because circumstances and life is just like that) and if the wife says anything about it i just take it all with a grain of salt
good luck dude and its not the end of the world ey