seacraft scupper question

[gaulois]

Hi folks,
Well, I picked up a 1973 SeaCraft Seafari, and expected worse for the price. Having said that, the boat has a 235 ob with a (well built) transom plate to increase to 25" to accomodate the engine. So here is the weird part. When I picked the boat out, there was a bit of water in the corner of the deck where one of the scuppers were. It seemed plugged up with debris, but it turned out that the previous owner had filled it with silicon. Same with the other scupper. I went underneith the boat and noticed that the scupper holes were covered with marine-tex. I used to have a '77 23CC so I assume that it is the same scupper design.
I had a long trailering trip down from Crystal River to Miami, and racked my brain the whole time as to why anyone would fill the scuppers. Once I got it home, I went over the boat and figured out what must be the reason. The 235 is too heavy, hence the 25" conversion, and that the dynamics of the hull changed and the scuppers took on water.
I have time to think about how I will deal with this as I am away. But a few questions arise: Do you guys think that I am right about the "why"? If so, assuming that the 235 has some hours left on it, is it even safe to have an engin that size on a 20ft? The "sinkcraft" joke comes to mind, and I have a feeling that it was because idiots put oversize engines on 20fters. Is there anyway I can restore the scuppers? I want freaking scuppers, is that too much to ask?". Should I just face the fact that having a 235 on the back is going to pose more problems than it is worth, and get what I can for it, and get a 150-175? I had the carbs rebuilt, and the engine seems to work well, although I have not been in the water with the boat yes (just picked it up).
Ok, enough out of me. I promise that I will contribute more to the site, sorry about my absence.