[Speedbumpauto]

"i agree with the parts list but i think you could build that for way less than 20k..."

With due respect, I think you're being a little optimistic....and you didn't say how close to FINISHED you are. I've got 10K in paint and body, but it's spectacular, IMO, and another 3+K in tires and wheels that are good but certainly not near the top. I've priced interiors and have found nothing decent under 3K, and I bought and modified the seats/console. If you want leather, it's 5K+.
I looked at a "shock wave" when I thought about bagging. $950 each, cheapest. The converter you're talking about at Summit is almost $1K and you didn't say where the 4L80 came from....

If there's anything I've learned in building these things, first is....they're never done and second is....they ALWAYS cost way more than yoiu thought and third....the way I want to do it is always the most expensive way to get the job done.
This is how I'm 7/8 of the way done with my "$60 thousand dollar $30 thousand dollar 55 Chevy pick up. If you get yours "sweet"(subjective term) and meet your $12K goal, I'll be the first to hoist a cold one to you.