Need some help with this one.....3.7 to 4.3 swap

[vincechig1975]

I am beginning the swap from the 3.7 to a 4.3, and my concerns are remeasuring the mounting distances and proper alignment of the new motor, now another issue or set of issues will be I understand that the inside plate that mounts to the transom and that the rear of the engine mounts to as well will be an issue but it's the alignment at the rear and the
proper measurements for the front mounts and making it so I can align it . Does anybody have some information that I might be able to use to do this swap?[/ATTACH]

 

[fuzzybob]

Re: Need some help with this one.....3.7 to 4.3 swap

Hook up the rear motor mounts to the transom with the front mounts on the engine then lower the front to the stringers and put the lag screws in.

 

[Pete104]

Re: Need some help with this one.....3.7 to 4.3 swap

Yea, you got made! The stringers are already set-up for V-6. Most times, it ain't that way.

 

[Bondo]

Re: Need some help with this one.....3.7 to 4.3 swap

now another issue or set of issues will be I understand that the inside plate that mounts to the transom and that the rear of the engine mounts to as well will be an issue but

Ayuh,.... Everything is based/ built/ aligned off that plate....

Once you have the right transom assembly, with the right inner transom plate bolted to the hull,...
With the front motor mounts in the center of their travel,...
Lower the motor into place, 'n stick yer alignment bar in-through the gimbel into the motor, 'n align it, on the hook...

That's where ya gotta build yer front motor mountin' blocks Up to....

 

[vincechig1975]

Re: Need some help with this one.....3.7 to 4.3 swap

Thanks all I appreciate the advise n the lil guy there is my right hand my helper, he's my boy. He is constantly asking me Dad are we gonna get this on the water.....and I keep tellin him you betcha. He is always handin me tools (even ones I don't need) but he does his best he took the credit for the old engine removal. a should've seen the look mom gave when he told her he got the engine spinner (prop)
out. That was priceless.

 

[Bamaman1]

Re: Need some help with this one.....3.7 to 4.3 swap

I have a 470.

You cannot put any other motor on the 470 transom mount assembly. To put a 4.3 into the boat, you'll need to have all three assemblies--engine, transom mount, and outdrive. The outdrive is also the wrong gear ratio for a 4.3.

In other words, you'll have to have a junk hull to transplant the parts over to your existing hull--to make the changeover affordable.

Leave it up to Mercury to keep it hard to do anything--and parts expensive.

 

[vincechig1975]

Re: Need some help with this one.....3.7 to 4.3 swap

nice:facepalm:

 

[Bondo]

Re: Need some help with this one.....3.7 to 4.3 swap

You cannot put any other motor on the 470 transom mount assembly. To put a 4.3 into the boat, you'll need to have all three assemblies--engine, transom mount, and outdrive. The outdrive is also the wrong gear ratio for a 4.3.

Ayuh,.... I disagree,....

The Gear ratio is No Problem, 'n will runn with the 4.3l, No Problem....
Ya just need the right flywheel cover, 'n a Y-pipe....

 

[vincechig1975]

Re: Need some help with this one.....3.7 to 4.3 swap

I found a used interior transom plate assembly and a bunch of other items to complete the swap, based on this info, I can get it and proceed, motor will be here in a few days,keeping the old one though and the parts for it. Thanks guys

 

[achris]

Re: Need some help with this one.....3.7 to 4.3 swap

I have a 470.

You cannot put any other motor on the 470 transom mount assembly. To put a 4.3 into the boat, you'll need to have all three assemblies--engine, transom mount, and outdrive. The outdrive is also the wrong gear ratio for a 4.3.

In other words, you'll have to have a junk hull to transplant the parts over to your existing hull--to make the changeover affordable.

Leave it up to Mercury to keep it hard to do anything--and parts expensive.

Poppy-****!!! The gimbal housing is the same (check the part numbers), the '470' uses a 1.84:1 drive ratio, the same as the earlier 4.3s. All you need is the Y-pipe for the exhaust and you are good to drop a 4.3 straight in....

 

[Pete104]

Re: Need some help with this one.....3.7 to 4.3 swap

I agree with Bond-O, that he's gonna need the F/W cover also. That may depend on which starter &/or coupler, too.

 

[vincechig1975]

Re: Need some help with this one.....3.7 to 4.3 swap

How about the drive shaft will that have to be changed? I am in process of rebuilding the interior of it ( the deck,stringers, and transom) and adding a few extras as well, I will also have a bunch of photos to upload later,

 

[achris]

Re: Need some help with this one.....3.7 to 4.3 swap

How about the drive shaft will that have to be changed? ....

Yoke? Depends on which one you currently have, long or short. If my memory is right, the V6/V8 uses the short, (8") yoke and the OLD in-lines use a 9-1/2".... It will depend on the year of the drive... Got a serial number?

Chris.......

 

[Bondo]

Re: Need some help with this one.....3.7 to 4.3 swap

How about the drive shaft will that have to be changed? I am in process of rebuilding the interior of it ( the deck,stringers, and transom) and adding a few extras as well, I will also have a bunch of photos to upload later,

Ayuh,... You should be Good to Go....

Only the GM Inline motors used the short shaft,...
The V-motors, 'n yer 470 used the 9"+ shaft...

 

[Leedanger]

Re: Need some help with this one.....3.7 to 4.3 swap

Serial...?