Tach Signal Wire In A '98 Gt

I sold an Auto Meter 5" tach to a guy at work who has a '98 mustang. I'm trying to help him get it hooked up.

So far I have found that on these models you have to pull the instrument cluster and tap into the tach signal wire, which is says is the orange and white wire. The other place I'm also seeing is right out of the PCM, which from what I gather is somewhere on the passenger side near the firewall..

I also saw where some of these cars need a tach drive module to work correctly, but I don't thing a '98 does.. just the '99 and up..

Is there any way to find a connection under the hood? I'd rather not pull the instrument cluster out if I don't have to.

Forgive me, I know nothing about fords.

It looks just like the one in this pic, two coils up front, each one has 4 plug wires coming from it:

Is there any way to confirm that we will, in fact, need a tach adapter? When I googled the topic I found that some said it was only needed on models '99 and after. The one you posted the video of does look just like it though. In fact, I was digging through that same bundle of wires that he is in the video looking for the O/W. I didn;t see it with a quick look, but I bet it might be there.

Evene when I called auto meter, they didn't say anything about needing a tach adapter. Don't you think they would have mentioned it?