So about a year ago my friend and I did this conversion on my vr. It runs great so far. Recently I've tried playing around with the spark plug gaps... It already had NGKR5s gapped at .35, then when I did my tune up I put on NGKR7IX plugs which give me a higher range since apparently the ford coilpack gives a much hotter spark. They come out of the box gapped at .35 but I regapped at .40 after reading up on other threads about coilpack conversions. It didnt make much difference than before except it driving a bit more responsive from the tune up. A couple of days after I regapped them at .50 and let me tell you, I can feel the difference. My MPGs went up from averaging 25-29 to 28-35 on the freeway. If you have a few hours to kill, I highly recomend doing this.
The coilpack was about $40 at the junkyard. DONT FORGET TO TAKE THE HARNESS PLUG WITH IT AND CUT ITS WIRES AT ABOUT 7'-8" just so you have anout to work with later. If you read though the previous posts it'll tell you which cars to look for the part in. I was lucky to find on with the long posts so I didn't have to modify my plug wires. Here are some pics I took while doing the whole project.
This is the coilpack itself.
Top view with the firing order.
Here's the harness from the ford coilpack attached to the original vw base with ICM. Notice how the wires from the harness are to be attached in order to the ICM.
Some people were complaining about clearance with the wire guides also I found out heat isn' the ICM's best friend. So I made a supporting plate that would give the coilpack and wires a better position in the engine bay. After I mocked it and knew everything would be ok in place I painted the plate black with some heat resistant enamel.
Here's how everything sat when installed. Make sure to run a ground wire from somwhere on the coilpack to the block.
Better view of the whole setup.
I know this "DIY" wasn't the most thorough one. But this is a very simple project. If you inform yourself enough, I don't think there will be a problem getting this right.