I rebuilt the Super 90 engine from our 1960 T5. I am an amateur, but documented most of what I did. Maybe it will help you. If assembling yourself, I highly recommend the Harry Pellow (aka Maestro) videos and his book The ABC’s (and 912’s) of Porsche Engines
The engine was far from original, save the case, heads, and carbs. I took it back as close to original as I could. Where I had to make choices, I did a lot of research, got advice from this forum, and checked some references. I'm happy we went with the following. The engine has run quite well on a stand. These links the might save you some time.
- AA Performance Products 86mm Porsche 356A & B Big Bore Piston & Cylinder Kit (note 22-degree for Super 90 head)
- Carbs went to Carb Rescue
- Cam went to Elgin
- Rods were used 356C / 912
- Distributor came from John Jenkins (affiliated with carb rescue)
- Heads went to Ollies
- Generator went to Zims
- AA crank
- Oil cooler from Wilhoit. Needed stepped studs to avoid drilling an early case for 8mm studs.