Block swap question

[Arrowglassrestorer]

Just found out today that the 1988 alpha 1 3.0 block is cracked in a boat I am restoring. I do have on hand a 1977 mercrusier 3.0 block that is rebuildable. Will this block match up to everything on the 88. I also have the crank shaft to this block. Can I use the 88 crank shaft with this 77 block?

 

[Bondo]

Ayuh,... The long block motors are a plug, 'n play swap,....

Ya can't mix, 'n match blocks, cranks, etc. without machine shop grade measurin' everything to know whether they're swapable,...

That said, just rebuild the '77, 'n run it,...

 

[Arrowglassrestorer]

I would take the block to the machine shop anyway just to get it spec'd out. What I was concerned about was, would this block match up to the 88 head, flywheel, etc.

 

[Scott Danforth]

by the time you add up the cost of machine shop time, new pistons, rings, bearings, gaskets, etc. you would be many hundreds of dollars ahead to find another running pre 1991 motor from a junk boat and bolt it in and go boating.

a rebuild on a 3.0 is about $1500

 

[mickyryan]

Rebuilt is way to go with a factory fresh block , since the blocks are all prone to rotting out unless you know the block is in great shape i would seek out a rebuilt or a running model to get ya by for summer.
to answer your question yes all parts would fit between the two but would need to check clearances as he said to be sure its a proper fit and have parts machined that don't or replaced.
All that said, they are great engines i have 2 in my shed I'm holding onto to rebuild some day maybe when I'm bored