Engine swap

[Geb123]

Can I replace my 4.3l gm engine with a 305 ci v8 in my 88 excel 20SL boat that has a Volvo penta outdrive

 

[boatdoc55]

Gear ratio is different in the drive.

 

[RicardoMarine]

Short answer.... yes!


Verify the following:

enough space for the longer 5.0L engine.
drive ratio...... (the 4.3L may have used the 1.61:1... if so, you can use that ratio w/ the 5.0L)


Keep in mind that after 1986, the SBC went to the later style crankshaft, of which means that the flywheel also changed.
Either way, you'll need the correct 153 tooth ring gear flywheel.


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[Geb123]

Short answer.... yes!


Verify the following:

enough space for the longer 5.0L engine.
drive ratio...... (the 4.3L may have used the 1.61:1... if so, you can use that ratio w/ the 5.0L)


Keep in mind that after 1986, the SBC went to the later style crankshaft, of which means that the flywheel also changed.
Either way, you'll need the correct 153 tooth ring gear flywheel.


.

it does have the 1.6:1 ratio but my flywheel has 178 teeth

 

[RicardoMarine]

1...... it does have the 1.6:1 ratio
2...... but my flywheel has 178 teeth

1.... Perfect!

2.... I know of only the 153 and 168 tooth ring gear flywheels for the SBC engine.
Perhaps a typo.... and you intended to type 168.

If the engine is fitted with the 168, then the later charcoal gray colored flywheel cover has been installed.
If so, this will be a single bearing PDS with a sealed bearing and pilot nose w/ crankshaft bushing.

This PDS is fully removable without engine removal.


BTW and FYI:
the 153 tooth flywheel = the starter motor with the straight across bolt pattern.
the 168 tooth flywheel = the starter motor with the staggered bolt pattern.



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