OMC outdrives ???

[lilsquirt]

Working on my dads 78 Orion 17.5 foot open bow ski boat. It has an omc outdrive on it for a v-8 and we wanted to change the 305 out for a late model 350 chevrolet. We built a motor and now it wont go into the boat. There is an adapter in the center of the flywheel that goes over the shaft in the bellhousing but this wont work on the late model crankshaft. Does anyone know of anybody who has a replacement hub? Do they exist? I assume this is an omc only shaft or I wouldnt be having this problem. Dont know a whole lot about outdrives being a jet guy but hoping someone can help. Thanks for any input.

[Speed955]

Try these guy's, my dad and I got older OMC parts we needed from them.
http://www.sterndrive.info/

[lilsquirt]

Try these guy's, my dad and I got older OMC parts we needed from them.
http://www.sterndrive.info/
Thanks, Ill call them in the morning.

[pocketchange 22]

Chevy 305, 307, 350, and small block 400's are all the same block dimensions.
the block came out, it should go back in.....
Only time u may have a problem is going to a big block, they are about 4'' longer in front of the motor mount. just my .02
Did you go from an "internally balanced" to "externally" if so the end of the cranks are diffrent diameters.
Can't figure exactly what the problem is..

[bikerboater]

Chevy 305, 307, 350, and small block 400's are all the same block dimensions.
the block came out, it should go back in.....
Only time u may have a problem is going to a big block, they are about 4'' longer in front of the motor mount. just my .02
Did you go from an "internally balanced" to "externally" if so the end of the cranks are diffrent diameters.
Can't figure exactly what the problem is..
It's not the block that's his problem I believe. Chevy changed the crank design when they went to the one piece rear seal. I'm not sure of the exact year but I think it was in the late 80s, like 87 up. Anyway, probably best to check out with an OMC parts source & see what they use for the later engines. Hopefully you just need a late style adapter piece.

[pocketchange 22]

YES, that is true.

[Tahiti350]

Lilsquirt,
I have an OMC 800 on the Tahiti. I've still got the older style crank though. the biggest caution is not to put TOO much power thru them. I've been told repeatedly that I'm not just pushing the limits, but that I've gone over the edge. I'm not in the 60 MPH range, swinging a 21+ SS prop, turning the motor around 5900rpm. OMC's are getting expensive, when you can find them. On the good side then only problem I've ever had with the drive was the lift motor shaft broke. $17.50 and about 1 hours work and it was good to go again. I did have to manually release the clutch pack... not fun to put back together.
I've got extra prop's so don't buy any without talking to me first. I have a 15x17, 14.5x19, and a couple of others, including the removable hub style in a 23 pitch.