Which lower unit do i get?

[scibz401]

Hit a rock yesterday out fishing and my lower unit is cracked basically in half. I need to replace it but i have no idea how to know which one is the correct unit. I actually found one locally for 300$ im really hoping it would fit!

1999 Mercury force 40hp
serial OE359169
gear ration 2:1

Heres a cut from the ad : [FONT=&quot]1643-6458 the shaft length is aprox 26 1/2 [/FONT]

Thanks for anyone who can help! Where can i find my "casting number?"

 

[roscoe]

I would help to see the entire ad.
provide a link if you can.

 

[jerryjerry05]

According to the parts crossover the only ones you can use is the 98 and 99 model.

A casting # will tell you maybe what year it was cast but not the year it was used in.

​Just took apart a 1988 125 Force.
ALL the casting #s were 1987.???

 

[scibz401]

The original one i looked at would not fit, i need the exhaust to exit at the prop, i guess that lower did not have that.

 

[pnwboat]

I see some on the auction sites but judging from the asking price on a few of them, you'd think they were made out of gold or something.

 

[jerryjerry05]

It's a shame what people are doing on the auction sites.

​Couple of years ago an exhaust manifold for a Ford Cobra $1000 used.