vintage outdrive question
 

I am trying to find out some info on stern power outdrives, or marine drive systems does anyone out there knopw any info on these. I am wanting to know if anything is availible for these?, if they were ever any good or not?, how much power they will handle? They are on a 1978 24-26' sonic with twin bigblocks. I have pictures but can't post them because I just have the regular membership, but I can e-mail them. I am also looking for any info on this boat. It was for sale a while back around bristol, TN I seen it on a web site for sale a few months ago but I can't remember which (I was just browsing)
The boat is black with blue stripes on the side & a white upper deck. It has no interior and needs a good bit of work. However the drive train looks suprisingly good. I figured this boat would be pretty rare considering its size with two bigblocks, maybee someone will have some info. Anything would help a ton Thanks Guys!!