Swapping 88' 454 Truck Engine to Replace 93' Mercruiser 454

[CLi87]

After multiple issues with the engine in my boat I've decided to just swap the block and heads out. My neighbor just happened to have an 88' 454 motor (Gen IV?) from a suburban with 100k miles sitting around so I got that from him and stripped it down. I know I have to move the accessory components over from the Mercruiser engine and the camshaft needs to be moved over but is there anything else? Oil pan looks roughly the same, are the valves/springs any different? Anything else I need to swap from a Gen V boat engine to a Gen IV truck engine?

 

[Scott06]

After multiple issues with the engine in my boat I've decided to just swap the block and heads out. My neighbor just happened to have an 88' 454 motor (Gen IV?) from a suburban with 100k miles sitting around so I got that from him and stripped it down. I know I have to move the accessory components over from the Mercruiser engine and the camshaft needs to be moved over but is there anything else? Oil pan looks roughly the same, are the valves/springs any different? Anything else I need to swap from a Gen V boat engine to a Gen IV truck engine?

Head gaskets and core plugs are likely different between a truck engine and a marine engine. Generally cam should be similar enough to marine if its the factory truck cam

 

[Scott Danforth]

Oil pan from a gen V is no where near going to fit a Mark IV block

You will need a Mark IV marine pan

I personally would look for a Gen VI motor to replace a gen V

 

[Comogene]

No need to change the cam as the truck one is close to the marine. At some point in the production, the Gen Vs started using roller cams, I think and there was change to the coolant passage holes, so the Gen V heads may not be able to be transferred. Have the Mark IV heads rebuilt and the flat tappet valve springs on the truck engine are fine. Core plugs will need to be changed. If the Mark IV pan is in decent shape, use it. The Mercruiser pan had the ability for the oil dip stick to be on either side. Standard Mark IV pan on had tube on passenger's side. Transfer Thunderbolt system and exhaust.

The Gen V intake manifold should work as the truck carb is a no-no.

Gene

 

[itsathepete]

Oil pan from a gen V is no where near going to fit a Mark IV block

You will need a Mark IV marine pan

I personally would look for a Gen VI motor to replace a gen V

I agree with Scott. Just helped a buddy swap a Mark IV in place of a Gen VI. A lot of the bolt holes were different sizes, and sensors had to be relocated as well. A lot more work that wasn't worth it in my opinion