repowering my 1980 f233 interceptor

[bill pugh]

I am considering putting a 454 mercruiser into my 1980  f233 has anyone done this conversion before...i have available to me a running 7.4...or a 454 mercruiser motor i tweaked the old 350 enough..any information would be appreciated...thank you in advance

[richard]

bill...  i'm pretty sure it would be a fairly easy conversion, except i assume you're running an alpha drive.  merc had durability problems with alphas behind bone- stock 330's in the mid 80's (especially on heavy boats like ours.)  you'll probably have to upgrade to a bravo 1- which will require replacement of inner and outer transom plates and the installation of an engine- mounted raw water pump.  good news is that the transom cutout is the same (think you have to drill two additional holes.)  only other potential issue is i think the vertical distance between the drive input and output shafts is 1" more on the bravo- putting the prop deeper in the water (not good for top- end numbers.)  think you'll have to upgrade the drive ESPECIALLY if you're planning to "tweak" the engine.  my '79 intercepter was built with a 330 merc with trs drive.  the motor's since been bumped to around 525hp and the drive has no problem handling it.  my "weak link" is the merc 2 "shorty trans.    good luck- - keep us posted....   Rich.