Mercruiser 7.4 MPI (1998) red top covers Red VS Blue

[dinopaul]

Hello everyone,
I need to change my tired engines, two 1998 Mercruiser 7.4 MPI in shaft line my engines are with blue top covers and I found a pair of 7.4 MPI Mercruiser but with red top covers, I was told that with the red top covers was for engines with Sterndrives, anyone know if I can make a plug and play or if there are modifications to be made.
Thank you for your help

 

[scoflaw]

You talking the difference between the L29 and the Mag?

 

[Bill Curtis]

Maybe the std vs: Blue Water versions

 

[dinopaul]

between these two versions

 

[scoflaw]

Same thing

 

[dinopaul]

I currently have the Blue with shaft, need to change the ECM ?

 

[scoflaw]

put the engine numbers in mercruiserparts.com and compare parts.