The "regular" Astro in 2003 used the "extended" bodystyle: the short Astro was discontinued in ... 1992, maybe?
The following is a partial list of 2-inch, Class III/IV, receiver-type hitches fitting the Chevrolet Astro, using factory holes for mounting and require no drilling:
Hidden Hitch (# 87516)
Quality S (# 023)
Reese (# 44010), (# 33057)
The installation notes indicated that my hitches (Reese on a 1992; Hidden Hitch on a 1994) would require relocation of the full-size spare; however, I was pleasantly surprised to discover that both of my installs allowed me to keep my full-size spares (I use P225/70R-15 on my Astros). I had planned to stow the spare inside until I could mount a "Continental kit" to the rear door, but I didn't have to: the OE location worked for me.
Please note that minor variations exist between some Astros and Safaris and other Astros and Safaris, depending on when & where the particular vehicle was manufactured. There have been some reports that not every "100% bolt-in, uses on the factor holes" hitch will so fit every Astro and Safari.
Since you're asking about a 2003, it may be worth mentioning that I've never heard of the alignment problem applying to 2003 models, and I'm not entirely ready to believe that everyone reporting an alignment problem knew what they were doing. It isn't rocket science, but some basic tips will greatly help:
(1) Read and understand the directions that come with your hitch. Some instructions are poorly written, but the meaning should be obvious from underneath the van.
(2) When bolting the hitch into the van, loosely Start All the fasteners (nuts, bolts) Before Tightening Any of the fasteners. IMHO, it is the failure to do this that leads to 99.9 percent (or more) of all claims that the holes don't align properly.
It will work as long as it fits.
A 60 inch toolbox.
Probably a 10mm. A six point would be best.
700-R4
Yes, if it fits the holder.
With a few bucks, anything you want to put in fits.
One Lie Fits All was created in 2003.
nv3500
Most likely a 4L60E
factories are 14''
Fram pH 35
5x108