I'd say it all depends on if you want to use NOS and excellent or restored OEM parts, or if you are OK with using reproduction parts?
These days you can darn near build a Challenger or cuda from scratch using reproduction parts if you were so inclined.
The supply of OEM parts is drying up and getting thinner every day. And the prices for some parts is beyond crazy for some parts if you can find them for sale. I recall an article about a hemi cuda Dave Walden restored around 10 years ago and in the article he said the price he paid for NOS exhaust headpipes for his build "would buy a new compact car".
There was an article in Muscle Car Review recently about a concours '71 hemi cuda restoration, where the shop mentioned about how hard it was to locate NOS correct 15x7 trim rings. They found them, but I'm guessing they paid 4-5,000 for the set of 4.
The same shop restored a hemi Superbird which was featured on the cover of MCR not long ago with the headline "Could this be the first million dollar superbird" and I had to laugh, wondering if that is what the bills added up to from the shop to do that restoration!
I just completed a restoration of a Challenger that I'd started back in the late 90s, and due to setbacks and bad luck I've discussed several times here on the board, ended up taking 16 years to do. I have mostly OEM parts on the car, and I look at it, and think I am glad I did most of my parts chasing early on, because I just can't imagine finding a lot of the parts on the car if I was searching for them now. Or how I'd pay for them if I did find them!
There are a ton of excellent repro parts available on the market now, and we should be thankful for that. However I have found on some of the parts I used the quality is bad, a lot are good quality, but some aren't. I had both leaf spring shackles and exhaust clamps snap like twigs when I went to tighten them for example.
