I know the changes aren't major, but I'm wondering what exactly changed
in 2000 on the version of the 3400 SFI engine used in the
Venture/Montana/Silhouete, Grand Am/Alero, Imapala/Monte, etc.
I seem to remember reading something about revised heads, and perhaps
some updated emissions stuff, but the specifics escape me. Do any of
these changes render the newer 3400 unusable in models that used the
I'm looking into dropping a low mileage used 3400 into a 97 Trans
Sport; and I'm wondering if the 2000 and up version will be a direct
drop-in, or if the 96-99 version is the only one that will work.
Specifically, would using the newer 3400 require a new ECM, or will the
97 work? Are there any new sensors to worry about? That sort of
http://www.3400swap.com/ has a "how-to" guide for swapping a 3400 in
place of a 3100 into a 94-98 Grand Am, and it seems to suggest any
version of the 3400 is more or less a drop in for the previous 3100 SFI
(and presumably the earlier 3400 SFIs), but any insight would be
Thanks for the help.