"I'm seeing $3900 in parts,"
Plus the two MAf's at $350 or so each, taking the parts total to $4,600. More than likely there would have been other parts that were needed.
I would have made the V12 work, but that amount would get me a 100k mile engine trans that would certainly need more attention sooner than later. Plus the fact that it would only put 320 to 330WHP with no to little room for performance modification. All of the LS1 swaps I have done regularly put 320WHP stock. A cam change will net at the minimum 20WHP. This "Van engine" is nothing more or less than an LS1 or LS2 with an iron block. All other parts are the same, it is just 75lbs or so heavier, but still weighs much, much less than the M120.
I am not knocking the mechanical side of an M120, but the electrical works leave much to be desired. These engines were designed in the late 80's, and the electrical engineering in the early 90's. The more complex something is, the more chances it has to fail, and mine did. The fact that there are'nt many 600's makes the parts expensive. (I have had this discussion before, and it has come up again with the motor mount cost $45 for the SL500 vs $100 for the SL600
) The parts that are used are in the same condition that I have, not usable.
If I can make a car that is faster, gets better fuel mileage, is more reliable, and less expensive to work on, what is the big deal? Better yet the Jed Clampett Express R129 (as it will be reffered to from now on JCER129), will be One of only One, much more exclusive than any run of the mill Sl600. I will go out on a limb and surmise that most who have purchased sl600's did it for the increased HP, and exclusivity, but not for the mainenance cost
Maybe some enjoy spending money and time to repair these things, I don't.
I will track the cost of this for those who want to know. This endeavor is not for everyone, but I will find out what the cost, performance, and fuel mileage is. On a side note, what do you think the Ferrari guys will say when I find a Magnum PI 308 or newer 328