Switching outdrives, new one wont go back in

[thestigmach1]

I have a 1969 boat that I swapped a v8 into from a i6. I bought an outdrive with the 1.5 ratio to put in it since the v8 would supposedly tear the 1.62 to shreds. I had aligned the engine and the old one slid in perfectly. (At this point I didn't have the new one) now that I have the new one I pulled the old one out and tried to sleuth the new one in, but will not go. Everything is lining up and the shaft slides partially into the coupler but that's it. I thought maybe the engine got out of alignment somehow and tried putting the old back in and it slide in fine. I don't understand what the problem is and is really frustrating because that's the final peice to taking it out on the water. The new outdrive is from a boat that had a Ford in it, mine is a chevy. Does that make a difference? Thanks

 

[alldodge]

Are the spline count the same on the drive shaft

 

[thumpar]

There were 2 different driveshaft lengths. Try measuring the difference. Just an FYI the V8 will not shred the 1.62 drive. Most 305's came with the 1.62. The only difference is the ratio. Going for a ratio that is one step up or down can usually be overcome with a prop. It is when you get 2 or 3 ratios off that it makes a big difference because you can't make up for it with prop and even if you can come close you will be running un-efficiently.

 

[thestigmach1]

I went with something much bigger than a 305 though, otherwise I would've left it with the 1.62 and went with a higher pitch. And everyone keeps telling me it's going to shreds it, I personally didn't see how that small difference could shred a gear but whatever. Just went and measured real quick and sure enough the new one is much longer than my old one. Que the cuss words hehe haha. Never would've thought of that. Back to the drawing board I guess. Thankyou for your help.

 

[thestigmach1]

Are the spline count the same on the drive shaft

Sorry I didn't see your post before, not getting notifications for some reason. Yes they are the same, first thing I checked when it wouldn't go in. Any one know if it's possible to make the longer shaft work? It's hard to find an mc1 around here that's in decent shape, much less entire outdrive assembly transom plate and all for 125 like I got this one.

 

[Bt Doctur]

The short/long shaft length was dependant on the coupler used on the engine.Try using a triangular coupler and not a crank mount coupler or swap the driveshaft from the drive.
Dosent have to be the MC1 drive, Alpha 1`s just bolt up.

 

[thestigmach1]

I'd rather not change the coupler because then I have to pull the engine again. It's in there and it's happy and I really don't want to go through that mess again. What is the process to swap the driveshaft? I couldn't find a reasonable alpha 1, I'd like to have one of those instead, they're generally stronger right? I had to be special and convert a sbc 400 to marine, so I'm running more power, torque really, than the standard mercruiser 5.7

 

[Bt Doctur]

Remove the C clip from the U joint, press the joint out, same way you would do a car driveshaft

 

[imp0ster]

I had to be special and convert a sbc 400 to marine, so I'm running more power, torque really, than the standard mercruiser 5.7

FYI my friend had a constant overheating problem in his Chapparal VIllian 20 so we pulled what we thought was a 350. It was a 400 bored 30. The siamese water jackets coupled with the boring made it poor for running constant high RPMs.

Keep an eye on that temp gauge

 

[thestigmach1]

FYI my friend had a constant overheating problem in his Chapparal VIllian 20 so we pulled what we thought was a 350. It was a 400 bored 30. The siamese water jackets coupled with the boring made it poor for running constant high RPMs.

Keep an eye on that temp gauge

I don't think this one is bored but plan to keep a close eye on it. I bought it thinking it was a 350 but didn't run the numbers on the block until I got home. I plan on putting a closed cooling system on it once i know that it will be successful. As far as changing the shafts I will try that once it stops raining and give you guys an update.