what is the difference between a 4.3 Gen II engine and a gen + engine

[2004 searay]

hi all, im trying to order parts and get torque specs on an engine and they are giving different torque yields based on the 2 different descriptions, i have no serial # to look it up, i know the boat is a 99 and the engine is a 4.3 vortec with balance shaft

 

[makomark]

the GenII's are earlier than the Gen+ versions...with a 99 hull, you very likely have a 98 or 99 engine and that should be the Gen+ flavor.


If you can get the engine code off the block, that would help a whole lot in terms of ID'ing what you have...should be on the front of the block, just below the head gasket...

 

[louc]

The number on the front of the block is a serial number, I think the one you need is a casting # which is on the rear of the block behind the cyl head on the port side
The cyl heads also have casting #s as well

 

[Dieter]

Not sure what gen II means but gen + is 96 and up vortec heads and 8 bolt intake.

put your merc serial in here https://www.marineengine.com/parts/mercruiser-stern-drive/index.php

if you click on the all engines and drives on rh side of that page it will show yiu what years were gen ii and gen + , your serial will bring you to exactly what you have

 

[louc]

Don’t forget there is a Merc serial # that is separate from the GM serial & casting #s.
AFAIK the torque specs that changed when going from the pre Vortec (up to ‘95) to Vortec (96 & up) were head bolt specs and intake manifold specs. The head bolts torquing procedure changed & the intake manifold specs changed from 30-35 ft lbs (Pre Vortec) to 11-15 ft lbs (Vortec).

 

[2004 searay]

Don’t forget there is a Merc serial # that is separate from the GM serial & casting #s.
AFAIK the torque specs that changed when going from the pre Vortec (up to ‘95) to Vortec (96 & up) were head bolt specs and intake manifold specs. The head bolts torquing procedure changed & the intake manifold specs changed from 30-35 ft lbs (Pre Vortec) to 11-15 ft lbs (Vortec).

yes but the torque specs from gen II to gen + changed on the head bolts, main caps and connecting rods