Has a 28 or 30 ever been built or repowered with 350sci's? Are they too much weight for the 28?

Not only the weight, but I dont think the lowers would hold up.

There was a 28 built with a single inboard

Ocean Ouboard did a 32 with Verados and it did work out well. Re-rigged with 300XS.

For how long and why was it rerigged?

Not very long because it was a pig. It was re-rigged so the boat could run and they could sell it. Tony from Ocean Outboard would know best and could tell you why. This was maybe 4 years ago.

Rick any info on that 28?

I have 350's on our 34 Fountain cc. The motors are strong but the gear case sucks. They blow out/hit a wall at around 83 mph. Water pick ups not great either. Motor mounts mushy made for pleasure boat. I thought about them for the 30 with the gear case but way to heavy for the 28.
If you could get solid mounts and the right gear case hp is good.
Redline is 6800 rpm.

the 28 was an old race from norway i think

And pics? Thats intresting