I was a member for many years on that site back in the mid to late 90's into the early 2000's. It was very active at one time and had some very knowledgeable people. Not that this will help your valuation question, but it was confirmed years ago that the '71 429 Mustangs did not come from the factory with an oil cooler. Some added them from over the counter parts, but, the group at that time did not pursue this topic much further at that time. The moderator of the site is still with us, but, he does not look after the site much anymore. The site was left up for information purposes and has some good information on it, even today.