Need advice on swim platform bolts 81SN

Morning. I've looked the site over and haven't found a link to this particular problem. I have an 81 SN and the top bolts holding the bracket and swim platform to the transom are loose. I have already used 3m 4200 on the bolts. I put the adhesive in the original bolt hole as well as on the bolt, and left it alone for a couple days. It worked to hold the bolts to the bracket, but the bracket still has movement away from the transom.
I'm worried about the weight on the bracket/platform when people are on and using the platform (as well as water intrusion). I have been thinking about 2 solutions, and wanted more experienced opinions on them!
option 1 - clean out the used 4200 from the original bolt hole and put fresh 4200 in and use a larger diameter bolt to hopefully grab/fit better. The bolts are only 1.5 inch long and do not to through the transom!
option 2 - clean out used 4200 and drill through the transom and use through bolts and nuts with rubber gaskets and more 4200 so no water seepage! (not a fan of make a new holes in the boat and then filling them but...)

Any fore site, opinions, or other suggested solutions welcome!

zwoobah wrote: The factory platforms are through-bolted for the top two bolts on each bracket. The lower bracket bolt is just a self tapping screw - the top bolts carry the load. Use stainless bolts and good sized washers. You may have to pull the fuel tank for access but it's a fairly easy job. Sounds like someone added a platform to your boat and used lag bolts instead of through bolts

Lag bolts are common in early eras. Through bolts are not.

8122pbrainard
Thanks for that, I was wondering because the inside of the transom doesnt show anysign of bolts of even a glassed over area where they would have been.

Would you suggest getting a bigger lag bolt or another suggested fix?

Thank you

Great feedback. Thank you so much. I will definitely look into a bracket for the interior of the transom as well!