Cam only swap help

They need to be properly degree'd. Cam swaps on these cars certainly aren't an easy task.

If you're going to the trouble of changing the cams, why not install the rest of the "supporting cast" as it were? I feel like you're leaving a lot on the table.
Anyway, I'm not sure how similar the 4.6in the Mustang is to the 4.6 they built the "trouble some Triton on, but if it is, you don't need a bunch of special tools. The chain can be hung from a cut and re-bent wire coat hanger. You can move the tensioner back with a screwdriver.

Yeah, lack of funds, I totally get that. But with a new intake and a couple other toys down the road, you will get more out of it, but, that's another story for another time.
As for the problem at hand, IF the Mustang 4.6 is anything like the 4.6 "Troublesome Triton" (and I think it's the same block just different heads) if you have anywhere in the neighborhood of 10K on it, replace the chains - they like to stretch. and do the tensioner while you're at it. (surface wear) and re-time the thing from scratch. Your plan seems good on paper, but stretched chains will blow that out of the water, and make it impossible to time anyway.
Yes, people do get away with re-using the chains, especially with the phased cams, (and replacing those phasers are the main reason to take that bit apart) But those didn't come along in the Triton until 04. Well, that, and the early motors like to spit the spark plugs. Depending on how meany and which ones were spit, sometimes it was easier to take the heads off to sleeve it.