Before this thread drifts too far.
What bolts do you want to remove? It sounds like you want to remove the flywheel / flex plate.

From the pics that I have of a 104, the flywheel to crankshaft bolts are torx that require a " T " bit. ( the socket version is " E " ) I think there is a revised torx shape out there but I don't think that existed until the past 8 years or so.

Impacts on a torx are a bad idea, they are not so strong due to limited size relative to the thread and head / washer diameter.

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New info

I took a look at a actual 104 I have, the FW bolts are 12 point not torx like the ones in the picture I have. A regular 12 socket will do the trick.


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To make things easier, hit the bolt head directly with a hammer to slightly imprint the bolt head into the surface. Doing so breaks the "stiction " and slightly reduces tension on the bolt. Use a t handle breaker bar, with the bar centered, this allows you to apply the torque evenly preventing the bit from caming out of the bolt. This is critical with stuck bolts, pulling on one side wedges the bolt to one side increasing friction.

As for stretch bolts, ( torque to yield ) no special tools are required other than a regular torque wrentch for preload. Marking the bolt head for degrees, looking at the angle of the ratchet is usually enough. I preload TTY bolts to a torque wrentch then angles by eye and feel. Once you feel the torque level off, turning more does not make the bolt tighter because it is stretching.