50 mercruiser engine question

"Hello all, great site! I have

"Hello all, great site! I have a 5.0 Mercruiser with an Alpha 1 outdrive. I have a BIG problem, I removed all the drain plugs for the winter(I thought)Well you know where this is going-I have a cracked block, my question is since its a 305 mercruiser(GM motor) can I replace the block with a regular Chevy block. I have had the boat for a year now and also have a problem with the boat taking on water when its sitting, when its moving it takes on very little water, its coming in below the drive shaft, someone told me it could be the bellows? When I have the motor pulled I just want to make sure fix that problem also. Any help would be greatly appreciated"

"Block is the same as car or l

"Block is the same as car or light truck. Do you have a mechanical fuel pump? Most car and truck blocks after late 80s are no longer drilled for mechanical fuel pump. Two basic blocks for 305, old style 2 piece rear main seal, about 86 and older. New style block, one piece rear main seal, 87 up. Crankshaft and flywheel do not enterchange between the 2 style blocks. Same applies to 350 block."

I would go with a 350 replacem

I would go with a 350 replacement.

Do some research and look for a remanufactured marine long block. Try to match the year of the motor. Swap all the parts. If your motor was a 2bbl carb change it over to a 4bbl carb and intake.

The water issue sounds like a torn short shift cabel BELLOWS.

"Ayuh,....

I Agree complete

"Ayuh,....

I Agree completely with Everything Kghost said...

You need a new Block,..
A rebuilt, or New Long Block gives you a Brand New Motor,...
The 350s are probably Cheaper than the 305s, if not the Same price...

Same motor, Same boltholes, as long as you stick wit the Same Vintage..."

"apoligize for cutting in, but

"apoligize for cutting in, but I wanted to confirm your answer. If its a 1999 engine Merc 5.0 L, will a new long block need a lot more compartment space (for a 2000 Bayliner 2455). All parts are swapable just to confirm? Also is it compatible with a Alpha 1 gen 2. thanks"

"Ayuh,...

All of the SBCs a

"Ayuh,...

All of the SBCs are based on the same Block,...

A 5.0l or a 5.7l of Any vintage is the same as Any other 305 or 350 of that vintage...

Long Block for Long Block, they're Exactly the Same on the outsides..."

"Different flywheel on the one

"Different flywheel on the one piece rear main seal verses the two piece rear main seal older engine. Also three different intake manifold bolt patterns. 86 back, 87 to 95 and 96 up which is vortec. You can use any small block but if you are buying a long block you might need different intake or flywheel depending on year. Just buy replacement for same year as yours."