Repower Questions

[DaytonaSlickCraft]

I'm trying to repower a '73 Slickcraft that had a Ford 302 and Pre-Alpha outdrive. I've got a late model Chevy 305 ready to go, but I can't seem to find the correct flywheel housing / transom plate combination. The late-model chevy flywheel housing is has the mounting pads too close together. I just bought an older chevy flywheel housing that has the mounting pads too far apart. Is there a third chevy flywheel housing or do I need to replace the transom plate. I need a housing that has the pads about 12 3/4" center to center to match the exisiting transom plate, or I need a transom plate that will match either flywheel housing and still bolt to the Merc sterndrive (not sure what it is, but serial number on the side is 3699073). I'm not afraid of a little fabrication, but its not really practical to modify the cast housings. Any help would be greatly appreciated.<br /><br />Tom

 

[KaGee]

Re: Repower Questions

The Merc guys will know more, but I believe your gonna need a new bellhousing and transom plate. Gets ugly changing motor brands.

 

[Don S]

Re: Repower Questions

Find a new inner transom shield for a Chevy engine for your model transom shield.<br />Not real sure, but I think the yoke on the drive that goes in the coupler is also going to have to be replaced. You may also have issues with the exhaust Y swapping from a Ford to Chevy.

 

[DaytonaSlickCraft]

Re: Repower Questions

I'll try to get an inner transom shield that will work. I've checked the late model coupler on the drive shaft and all the splines mesh nicely. There is an exhaust y on there, but I'll probably remove it since it has been converted to through-hull exhaust. Thanks for all the help.

 

[Bondo]

Re: Repower Questions

The Chevy flywheel covers are 15" for the old model 1s, or pre-alpha,.... Which is Sort of the Drive you Have...........<br />The other cover you have is for an Alpha 1,... They're 9"s.........<br /><br />You'll need the Chevy, Pre-alpha Inner transom plate,....To go with the flywheel cover that's 15" between the bolts.....<br /><br />And,... Don's Right again,... The Y-pipe is Also Different,.... <br />Switching to thru-hulls,... You'll need to fab-up a block off plate,.. Water Tight.......<br /><br />And,..... Even though the spline count is the Same for All Mercruisers,..........<br />The Distance between the Flywheel,+ the Outdrive Is Different.................<br /><br />There you're in Luck,........... <br />Seirra offers a Coupler in the Old Style, with the New 3" Crankshaft Bolt Pattern...........<br />You'll be Needing 1 of those as well,........ Any NAPA can get it..................

 

[DaytonaSlickCraft]

Re: Repower Questions

Thanks for all of the great info. Will an Alpha inner transom plate bolt to a pre-Alpha drive? That would increase the chances of me finding a part. The block-off plate for the y-pipe won't be a problem.<br />The serial number of my drive makes it a pre-Alpha from what data I've found online.<br />I check on getting one of those couplers.<br /><br />Thanks Again,

 

[Bondo]

Re: Repower Questions

Will an Alpha inner transom plate bolt to a pre-Alpha drive? That would increase the chances of me finding a part.

I haven't Tried that,....... I Think it'll just cause More fitment Issues........<br /><br />I'm Pretty Certain that I have a Chevy Inner Transom Plate out in the wellhouse,.....<br />If it'll help you,.... I'll go have a Look......<br />I've parted out Several,.. Both Chevy,+ Ford powered Pre-alphas.......<br /><br />When I did Mine,..... I went to a complete Alpha Transom Assembley........<br />Your Outdrive will Still be useable,+ the Boat side of the equation IS updated to a more current set up........

 

[mkast]

Re: Repower Questions

Sell the 305, bolt a Ford 351 into the hull.