Oldsmobile 307 vs Chev 305 Engine

[Mike Keast]

I purchased an 89 Caprice Wagon with an Oldsmobile 307 Engine in it. I have
had to replace a few things on it such as alternator, etc. I just had a leaky
valve cover gasket which had to be replaced as well. The mechanic indicated
that it would cost about twice as much to replace as a 305 due to all the
extra hoses and things attached to it. ($250.00 Cdn) The alternator was very
difficult to get and more expensive than a 305 alternator.
Is there any advantages to a 307 vs a 305. Does it last longer? less
problems? Should I have stayed away from that engine?
Thanks Mike

[Dick Wells]

The 307 is superior in the valve train. It will go all the way without
leaky seals while I have never had a small block chevy that didnt start
blowing oil past the stems at around 60K.

[system admin]

Mike Keast (mikek@CAMSIM) wrote:

: I purchased an 89 Caprice Wagon with an Oldsmobile 307 Engine in it. I have

I concur with another poster's comment about the Olds' valvetrain being
more durable. The Olds 307 is a direct derivative of the '350 Rocket', which
is an extremely durable engine. There should not be a significant price
difference between the alternators; your experience might reflect
local availability. If you've every tried changing spark plugs on both
those engines, you'd immediately appreciate the Olds' placement *above*
the exhaust manifold. While the AC compressor brackets on the passenger side
do obstruct the valve cover somewhat, I would question a $250 charge to replace
both gaskets.

Kevin

[tle...@ior.com]

In <NEWTNews.828117...@mgkeast.inforamp.net>, Mike Keast <mikek@CAMSIM> writes:
>
>
>I purchased an 89 Caprice Wagon with an Oldsmobile 307 Engine in it. I have
>had to replace a few things on it such as alternator, etc. I just had a leaky
>valve cover gasket which had to be replaced as well. The mechanic indicated
>that it would cost about twice as much to replace as a 305 due to all the
>extra hoses and things attached to it. ($250.00 Cdn) The alternator was very
>difficult to get and more expensive than a 305 alternator.
>Is there any advantages to a 307 vs a 305. Does it last longer? less
>problems? Should I have stayed away from that engine?
>Thanks Mike

It's a good engine, at least as good as the 305. Both engines have their little
quirks. Leaking valve covers are common (replacing the cork gaskets with
either RTV or rubber-cork gaskets is a permanent fix) and sometimes the
intake manifold leaking around the front or back too. Neither of these are
serious flaws. The Chevy 305 has just as many, if not more, and more
serious ones (like a rear main seal that loves to leak, valves that love to
clatter, etc).

The one thing the Chevy has on the Olds is price. The chevy block is simply
much more common. You can go down to the local performance shop and
pick up an intake manifold. While they exist, the similar part for the Olds motor
is "special order" and generally costs more. Law of supply and demand.

But. . . I'm an Olds nut. I own an '84 Hurst/Olds with the high-output 307. I love
the car and the engine. It's powerful, torquey, easy to work on (ever tried to
change the plugs on a chevy 305? Not impossible like some transverse V6's
I've seen, but tons harder than the 307), and very reliable.

Tom.