Gen 1 305 swap with gen 2 4.3

[azafata26]

I've acquired a cheap 1995 Tyee Grand Sport 1850 in good shape. It has a cracked block 4.3 gen 2 mercruiser. Long story short, I stumbled upon a 1989 maxum with a bad outdrive but a good 305 gen 1 engine. The wife is happy about the 2 boats in the backyard.

I want to get the Tyee going. What would your recommendations be? Would I have the required supplies to install the 305 in the Tyee and junk the Maxum? Should I get a 4.3 block and throw the parts from the Tyee on it and hope for the best and find an outdrive for the Maxum and sell it?

Thanks in advance.

 

[Bondo]

I've acquired a cheap 1995 Tyee Grand Sport 1850 in good shape. It has a cracked block 4.3 gen 2 mercruiser. Long story short, I stumbled upon a 1989 maxum with a bad outdrive but a good 305 gen 1 engine. The wife is happy about the 2 boats in the backyard.

I want to get the Tyee going. What would your recommendations be? Would I have the required supplies to install the 305 in the Tyee and junk the Maxum? Should I get a 4.3 block and throw the parts from the Tyee on it and hope for the best and find an outdrive for the Maxum and sell it?

Thanks in advance.

Ayuh,..... Welcome Aboard,.. The simplest cheapest quickest way to go boating, would be to drop the 305 into '95, 'n go,......

 

[Scott06]

I've acquired a cheap 1995 Tyee Grand Sport 1850 in good shape. It has a cracked block 4.3 gen 2 mercruiser. Long story short, I stumbled upon a 1989 maxum with a bad outdrive but a good 305 gen 1 engine. The wife is happy about the 2 boats in the backyard.

I want to get the Tyee going. What would your recommendations be? Would I have the required supplies to install the 305 in the Tyee and junk the Maxum? Should I get a 4.3 block and throw the parts from the Tyee on it and hope for the best and find an outdrive for the Maxum and sell it?

Thanks in advance.

I did a 4.3 to 50/305 swap on a 2004 sea ray 200 sport. You need about 4” in front of the 4.3 as the 305 is longer. Side motor mounts will also be about 4” farther forward. My boat was offered new with 4.3 and 5.0 engine options so I had space in front and the engine mount stringers were long enough to accomdate the longer v8.i kept the v6 drive and went up 2” in prop pitch

so if there is space should be an easy swap

 

[Scott Danforth]

the 1995 motor should be a 168 tooth flywheel

the 1989 motor may be a 153 tooth or a 168 tooth. worst case, you need to get a flywheel. (look for a truck manual transmission flywheel)

If you have the room, should be a reasonably quick swap.

 

[nola mike]

the 1995 motor should be a 168 tooth flywheel

the 1989 motor may be a 153 tooth or a 168 tooth. worst case, you need to get a flywheel. (look for a truck manual transmission flywheel)

If you have the room, should be a reasonably quick swap.

Flywheels wouldn't swap over?

 

[Bondo]

Flywheels wouldn't swap over?

Ayuh,...... That depends,..... need the right starter bolt holes, but I believe which ever flywheel it has, the full bobtail motor will swap regardless,.....
'n the 4.3l flywheel is of a different balance,.....

 

[nola mike]

Ayuh,...... That depends,..... need the right starter bolt holes, but I believe which ever flywheel it has, the full bobtail motor will swap regardless,.....
'n the 4.3l flywheel is of a different balance,.....

Ah, true. Was mostly responding to scott's post. If you're dropping it in the starter is going with it. The 4.3 flywheel IIRC is not matched to the motor, ie the motor is internally balanced. Not sure about the 5.0? I think I was also thinking about the flywheel/coupler difficulties that can occur when mixing 3.0l vintages.

 

[Bondo]

Ah, true. Was mostly responding to scott's post. If you're dropping it in the starter is going with it. The 4.3 flywheel IIRC is not matched to the motor, ie the motor is internally balanced. Not sure about the 5.0? I think I was also thinking about the flywheel/coupler difficulties that can occur when mixing 3.0l vintages.

Ayuh,..... Some are, 'n some aren't,...... depends on the vintage,...
The 305, 'n 350 are neutral balanced,.....

 

[Scott06]

Ah, true. Was mostly responding to scott's post. If you're dropping it in the starter is going with it. The 4.3 flywheel IIRC is not matched to the motor, ie the motor is internally balanced. Not sure about the 5.0? I think I was also thinking about the flywheel/coupler difficulties that can occur when mixing 3.0l vintages.

if the guy is swapping complete bobtails even with crank vs flywheel mounted coupler wouldn't matter.

Pre '82 the rear motor mount spacing is different, but that is a different animal than what the OP has.