T the wrath Active Member Joined Sep 29, 2002 May 9, 2023 #1 Gnttype.org says its 4.1 but I googled it is says it's a early 3.8
WarWagon Caustic Cacophony Joined Mar 10, 2007 May 9, 2023 #2 TeamBuick resource, has that a 1979-87 3.8L
E earlbrown runs with scissors Joined May 26, 2001 May 20, 2023 #3 Measure the bore. stock 3.8 is 3.800" 4.1 is 3.965"
