It's 2 years since I sold my Ultima, but I still like to read this forum and I was interested to see that my "Cost of an LS7 Ultima" thread had been resurrected.
There are some interesting comments there, but the bottom line for any wannabee Ultima owner is to decide between the two main routes to ownership:-
Route (1) - You want a hobby that will take you several hundred hours but at the end of it, will give you an enormous sense of satisfaction for (hopefully) a job well done. I spent a lot of time and care over my "Factory-Spec" build, and in order to ensure that I ended up with a high quality result, there were one or two jobs that I had the factory do for me - They must have thought I had done a good build http://www.youtube.com/watch?v=9fRfBdz0_7Q
because they asked me if they could display my car on their stand at Stoneleigh in 2010.
You MUST go into Route (1) with your eyes open... the instant the car is finished and IVA'd, if you choose to sell the car, it is highly unlikely that you will get back the money that you have put into the car - hobbies cost money, and I treated it as a hobby that would cost me money .... and it did !!
Of course, if you decide to keep your Ultima for many years, you will still suffer depreciation, but it will be over a period of time, and may not be as painful..
Route (2)- You want to own an Ultima but you are conscious of the money aspect. In this scenario, you may be better off looking for a car that is being sold by a builder who has maybe let the costs get away from him and needs to sell the car. He will have suffered that first bite of depreciation.
I will give you an opinion about the engine and exhaust as well - I bought the engine (and the wiring loom and ECU) from American Speed, because it was guaranteed to fit into the engine bay and guaranteed to work first time, and guaranteed to pass IVA emmissions - and it did. I bought the exhaust from the factory because it was guaranteed to pass the IVA noise test - and it did.
I have read so many threads on here where people are asking about emissions or noise....of course if you want the grief and the challenge, then go ahead.... but I always say.. "you buy cheap, you buy twice"
There are plenty of "box-shifters" out there who, on the face of it, are selling cheaper - but they are not selling the complete package so you are not comparing like-with-like. There may be an opportunity for someone to replicate, here in the UK, what American Speed are doing, and supply a package for the Utima that is complete, and guaranteed to fit and work.... I said this on here a couple of years ago, and to my knowledge no-one is doing it...yet.
I have no connection with anyone mentioned in this thread - it's all just my opinion.
Best of luck to all prospective builders/owners.