Re: exhaust plates 1979 9.8 and 7.5 hp
You're better off buying new plates at a Merc dlr or online. The new ones are marine-grade alum and have a proper anodized coating on them for corrosion-resistance.
It'd probably cost you more to try and weld up a plate (nothing else is gonna work 'cept welding; J-B Weld or stuff like that, no way!) than it would to buy a new one, and if you did have one welded it'd be all warped and likely to leak.
At any rate, if you can't find any links to the part thru the Parts Pages at this site, check out the diagrams at this link:
http://www.mercruiserparts.com/SelectModelType3.asp?class_id=2
Looks like a new plate is just under $20 and you'll need inner and outer exhaust manifold gaskets to go with at around $3.65 per.
HTH...........ed
