Is there any difference in the engines??

[Buick_noob]

From 1984-1988 Just talking about the block and heads..??

 

[JDEstill]

my understanding, no changes at all to the heads, and a few minor things to the block.

Look here: Index to Photo Guides
and here: Buick V6 History

John

 

[Hot Air]

Block:
20 bolt oil pan & turbo oil drain hole (86-87) vs 14 bolt & no oil drain (84-85).
Conrad

 

[BlackBandit]

Didn't the 84-85's lack the oil groove on the front cam bearing?

 

[GNVAIR]

There was an 85 only 20 bolt oil pan block that still retained the rough cast lifter valley that the older 14 bolt engines had.