Bracket Remodel Questions

[CJg8r]

Looking for some input here. I had the lower unit let go on the yamaha 250 a couple of weeks ago. Picked up a semi matching clean engine last week for next to nothing with a knocking powerhead but the catch is that it is a 30" and I have a 25" motor. Currently my boat ('76 23' Sceptre) has a 24" deep fiberglass non-flotation bracket on it installed by the previous owner. As it is currently, the cavitation plate of the 25" motor sits within 1/2" of the bottom of the keel. I know that this is not ideal and should probably be 2-3" higher but have never wanted open up that can of worms until now. I am looking to transfer my powerhead onto the new to me 30" engine which is easy enough. My question to all of glass gurus of the site is can I modify the fiberglass bracket I have now to raise the motor 7" provide a swim platform and turn it into a flotation chamber or should I look for a new bracket. Ideally I would like not to drill the transom for a different bracket nor can I shell out $2600+ for a new bracket. Currently I have more time than money as I am a stay at home dad. My concerns with modifying the current bracket are that it will be structurally sound and that at the end of the day doesn't cost as much as picking up a decent used bracket.

Thanks,

Matt