I did a little part swap with seattletom this past week, temporarily exchanging one of his rear Thunderbird/Mk. VIII (MN12/FN10) rear uprights that have been beautifully cleaned up and reassembled by Stu Spencer at IRS Machining for my Fox Mustang power rack and pinion. The only non-standard thing about Tom's uprights, is that he has installed the 5x114.3 Cobra hubs in place of the stock 5x108 hubs. As near as I can tell by comparison to my pre-Stu uprights, this does not appear to have any effect on the dimensions other than the bolt pattern diameter and hub centric lip size.
This allowed me to toss* the upright on to the handy-dandy CNC CMM** at work, so that we could get some accurate measurements. There has been a small amount of rounding and/or averaging of on some dimensions, but even the most heavily averaged measurements will be within a couple thousandths of an inch from actual. And since we don't actually know the nominal dimensions or tolerance range on any of these, some of the dimensions will vary up to a few thousandths from upright to upright anyways.
Attachment:
2014-08-23 Upright Measurements 01 Sized.jpg
Attachment:
2014-08-23 Upright Measurements 02 Sized.jpg
* gently place
** Computer Numerical Controlled Coordinate Measuring Machine