From:
v8hawk_REMOVE_697686_THIS_@yahoo.com
Ok, words from Mr. Buick V-6 expert.
*grin*
First off, externally the 3.1, 3.8 and 4.1 are the
same. You have 3.1 and 3.8 in front wheel configuration
too. I don't recall and 4.1 liter front wheel drive
cars. Even verse odd fire. The odd fire has a differnt
distributer and cap. Odd fire had the connecting rods mounted
on the same journal like on the v8 cars. Even fire
had separate journals for the connecting rod. The
connecting rods on the even fire have the pin on the piston
side offset. You can't use the odd connecting rods in
the even fire engine. Also 1980 even fire roads have
beefier caps on them.
The 3.1 liter crank is different
than the other v-6 engines. The crank has a small
diameter bolt circle for the flywheel to attach to which
also requires a special Flywheel.
Buick went a
little nuts when it comes to water passages in the v-6
engine and changed the shape and postion multiple times.
You have to be very careful when swapping heads on
these engines. Head design once again changed for the
better in 1979, much better flowing heads. Intake and
exhaust ports are different on these new heads though.
The exhaust ports sit one inch higher on the 79 and
newer heads so you may have problems when trying to
hook the stock exhaust to these heads. pre 79 cross
over has different part # and is no longer available.
The exhause manifords are shaped a little different
too. You can't physically bolt the pre 79 manifolds to
the 79 and newer heads. If you have 79 or newer heads
on a 231 v6, you can take the intake manifold and
quadrajet from a 4.1 liter and use it on the 231(3.8), Keep
in mind though that the water outlet neck on the 4.1
liter manifold is smaller in diameter than the orginal
for these cars so you have to use an adapter to hook
the top hose to the radiator.
[This is message #82 by user v8hawk on Yahoo! Club Buick Skyhawk owner's Club:
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