Which 350? The LT1 or the older one?
Nevertheless, I'm pretty sure that in either case it won't work because: the
307 is an Olds engine, whereas the 350 is a Chev engine. The 307 has a
crossunder pipe linking the two manifolds together, while the 350 (to my
knowledge) does not, instead using a Y pipe to link the two sides together
in the case of single exhaust versions.
I used to have an 84 LeSabre... what a great car that was :))
I had it in my Buick too... but trust me: It was made by Oldsmobile. My
Cadillac had a 307 as well.
I think that it's a Y pipe that joins the two sides then... you should check
to see if the 307 headers will fit on the 350...
I know that you can safely transfer a 403(another Olds engine) into the
LeSabre because this is what I did. :)
Let's clear this up:
The 307 most folks are familiar with is the "corporate" olds 307.
Chevrolet also built a small block displacing 307 cubic inches from 1968
to 1973. It could be had in camaros and other intermediates.
The LT1 is a second generation small block displacing 5.7L (350). I
believe a 4.3 V8 variant existed as well (sometimes installed in
Speaking of earlier 350 inch engines, Chevrolet, Buick, Olds, and Pontiac
*all* had an example of the divisions' own designs. They are not the
same motor. Buick 350s were manufactured from, I believe, '68 to '75 at
least; Chevrolet's from '67 and still available (en masse...);Oldsmobile '68 to
'80; Pontiac '68 to '76.
The 403 is an Olds, and also a former "corporate" engine.
I couldn't find headers for the car (if hedman doesn't have a cheapo fit,
good luck finding one), but they may still exist.
Finding exhaust manifold may be tricky. While it is possible that one
might be found to fit precisely, I don't know of a particular example; to
my knowledge, Buick-built V8s were never installed in that generation
B-body. Regardless, find a buick manifold that looks 'close;' any
competent exhaust shop can mate, as long is they are reasonably clear of
the crossmember, them into the existing system in less
than an hour and $50.
The 403 is, however, a pretty easy swapover and they can be made to make
relatively decent power. They don't like massive power and high revs,
however; the block webs have a tendency to crack if built too far.
On Fri, 21 Nov 2003 18:08:53 -0700, Matt Keefer wrote:
The corporate 307 wasn't bad without all the plumbing... I remember that my
84 LeSabre could really go. I replaced it after a write-off with an 89
Fleetwood Brougham. It also had the 307. Jesus, what a shitbox that car was.
The ride made even me nauseous over long hauls, the dimpled leather seats
were impossible to keep clean, and up any steep grade, the car would run out
of power and ping like crazy. I'm not even going to bring up spark plug
You might want to check out this site:
Gives pretty good lowdown about the engine's strengths, weaknesses, and
tweaks. Apparantly, a 350 swapover is possible, as long as you change the
manifolds and exhaust system.
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