1972 165 Mercruiser Block cracked

[Sc25175]

I have a cracked block in my 1972 Starcraft Chieftain 24 footer. Engine is out on a stand.

Question

The casting number on my block is 328576 I have found a donor motor from a chevy truck that has a casting number of 3921968.

the only thing I have been able to determine is these casting numbers where both being made in 1972.

Is there any way to figure out if I could use the block from the donor truck for the boat??? Thanks in advance

 

[achris]

Re: 1972 165 Mercruiser Block cracked

Most of the differences between marine and non-marine engine blocks of this era were the front mount bolt holes. Any replacement block you find will need to have the 'ears' at the front for the mounting. Also make sure they have screw holes tapped for the starter motor...

Chris....

 

[Sc25175]

Re: 1972 165 Mercruiser Block cracked

I have confirmed that the bore and stroke for both casting numbers are the same. I am having the current owner check on the bolt holes for the front motor mount. He is also confirming it is a six bolt main.

Is there anything else I should be checking on? This could be a good deal $50 for a working motor.

 

[Don S]

Re: 1972 165 Mercruiser Block cracked

I have confirmed that the bore and stroke for both casting numbers are the same. I am having the current owner check on the bolt holes for the front motor mount. He is also confirming it is a six bolt main.

What the heck is a 6 bolt main? I know some V8's have 4 bolt mains, but 6 ?

 

[Sc25175]

Re: 1972 165 Mercruiser Block cracked

Sorry, used the wrong term. I meant 6 bolts on crankshaft to connect to the flywheel. Not much of an engine guy.

 

[Bondo]

Re: 1972 165 Mercruiser Block cracked

I have a cracked block in my 1972 Starcraft Chieftain 24 footer. Engine is out on a stand.

Question

The casting number on my block is 328576 I have found a donor motor from a chevy truck that has a casting number of 3921968.

the only thing I have been able to determine is these casting numbers where both being made in 1972.

Is there any way to figure out if I could use the block from the donor truck for the boat??? Thanks in advance

Ayuh,.... How far away is the donor motor,... Don't trust the seller, he won't know what "Ear" yer talkin' 'bout....

Study the forward starboard corner of yer motor block, then go Look at the donor motor...

 

[Sc25175]

Re: 1972 165 Mercruiser Block cracked

Thanks Bondo, the motor is 90 miles away so I am having him send me pictures, hopefully I can tell that is the same or different.

 

[Don S]

Re: 1972 165 Mercruiser Block cracked

Post that picture here when you get it.

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