No major progress to report on my project, though I did make another junkyard run and picked up a couple of useful parts.
Earlier in this thread I said I was slightly disappointed I couldn’t use the 70mm BBK throttle body from my 95 on the new engine. But I wasn’t disappointed enough to spend $150 on a new one that might not produce any more hp than the stock 65mm TB found on the Mustang, Explorer and 96/97 T-Bird.
After doing a lot of research, though, I learned that some 5.4-powered Ford trucks and vans came with a 70mm TB (probably the same piece as the old Ford SVO throttle body). CrownVic.net has an excellent post on which vehicles you should look for.
The local LKQ yard had a Black Friday sale, and their inventory showed four Excursions that might have the part I needed. Two turned out to be V10-powered and one was missing its engine entirely, but the last one had what I was after. It might not add any power, but for $26 I’m willing to risk it.
Externally, the 70mm and 65mm TBs look exactly the same, so you need to look for a label that says YC2U-BA or YC2U-BB. Without calipers, that’s really the only way to tell you’re getting the right part.
With calipers:
I also wanted to find a better MAF than the stock 96/97 sensor in the C&L 73mm housing I had in my 95. There’s no reason to go aftermarket here: Ford makes great electronics, and the best choice for my application (for reasons explained here is the one from the 02-04 Mustang GT. LKQ didn’t have any of those, but Ford ended up putting the same part on various trucks over the years—including, as it turned out, the same Excursion I grabbed the TB from.
Things to note: The 94/95 T-Bird MAF uses a different connector than later vehicles, so if you have one from those years, you’ll need to grab the female plug and a length of wiring from your donor vehicle. If you have a 96/97 T-Bird, you can use your factory wiring. Sort of.
All MN12 T-Birds have a four-wire MAF and a separate IAT sensor. The YC2F MAF has six wires because it incorporates the IAT and MAF sensors into one. You can just splice the wiring for your IAT into the new MAF sensor. It may be hard to tell, but the wires are even the same colors L-R, so making the splices couldn't be easier. Old MAF plug left; new plug right. The IAT wires are on the far left and far right of the new plug--you can see the old plug has room for them but doesn't actually use them..
And as minor a thing as this is, the new MAF is 12 oz. lighter than the old one. Not the reason for the swap, but I'll take it.