Tips for Olds
307(Y and 9), Buick 231, Olds
260, and "Universal Olds
(Y and 9)
There were two versions of the Olds
307 built. There is the 5A head and 7A head version. GM switched
to 7A heads in mid 85. 7A head engines had smaller porting and roller
lifters while 5A head cars had normal porting and hydraulic lifters.
After market intake manifolds won't fit on 7A heads. To check your
heads follow the negative battery cable to the head. The casting
can be found there.
Those of you with code Y 307's can
convert yours to a HO307 with a few part swaps as listed below (from
|Long Duration cam shaft
|High Rate Valve springs
|Rochester 4MV carb
|Dual Snorkel Air Cleaner Assy.
|Intermediate Exhaust Pipe
|Muffler and Tailpipe Right
|Muffler and Tailpipe Left
|2400 RPM locking stall converter
You can also swap the 307 block with
a 350 or 403 since they are physically the same size. Heads, intake,
exhaust manifolds, and accessories will bolt up. You obviously need
new pistons. I recommend some that will yield a little more compression
than stock, say 9:1. Use the proper crank for the new engine and
if money allows upgrade the cam too. You can't get too radical a
cam or else the computer won't like it. I believe two steps above
the stock HO cam is all the computer can take.
A performance computer chip from Hypertech
(Thermomaster) will increase the timing at WOT and delay torque
converter lock-up. There is a small increase in performance with
If you have a stock 231 in your Cutlass,
I'm sorry. I know they are pretty anemic. If swapping engines is
out of the question, there are some easy mods available. Take a
look around some salvage yards for a Buick 252. They can be found
in large Buicks and possibly big Oldsmobiles. (I found the one on
my old car on a 81 Buick Electra) The aluminum intake will bolt
right up since the 231 and 252 are the same blocks. The QuadraJet
provides more punch than the stock 2bbl. The 231 should have had
a 4bbl from the factory. (in my opinion :) When looking try to find
an intake/carb/air cleaner together. I was lucky enough to get all
three from the same car. The only possible problem with this mod
is the carb may have a different number of vaccuum ports. Either
too many (block some off) or two few (tee some hoses together).
This mod alone adds about 20hp and makes accelerating onto highways
and uphill much easier.
If you can find a pre-84 Turbo Regal
you can try adding the turbo to your car. Be sure to get all necessary
brackets and accessories as well. You also may want to check out
Kenne-Bell for parts. They specialize in Buick V6's as well as other
Buick engines. Might find some easy upgrades through them.
Suggestions for the 260 submitted by Eric Foght.
"Let's face it. The 260 is nothing more than a glorified
boat anchor. The only way to get performance out of the 260
is to fit it with all the necassary upgrades from the h.o. 307.
These upgrades would be, a bigger cam (at least a .488 .510
lift), 4 barrel intake with a carter, not a quadrajet, 2.02/ 1.95
70cc heads, you will also need to bump up the compression to about
10.5:1. then it will still be a dog, but it will run respectable
times at the track for being a 260 and it will be consistant.
The only way i would suggest upgrading a 260 (if the price is feasable) is
to pull the motor and replace it with a 307, or 350 olds, or i would
highly suggest a chevy 350. I have a 305 chevy motor in mine.
My 350 is in the machine shop. I suggest the 350 chevy motor
simply fot the fact that it is one of the cheapest and most common
motors around. If you get a chevy motor, you will also
need a chevy transmission. You could get both from a local junk-yard
for about $400. You will also need to go to your local
auto parts store and get a set of 81-88 monte carlo motor mounts.
It is a simple bolt on from there out. Chevy 350 parts are
much cheaper than oldsmobile parts. Face it, it would be cheaper
to go with a chevy motor in a cutlass. The upgrades are endless
in both chevy and olds 350's, but it is much easier to get
parts for a chevy motor."
Thanks Eric! I would also like to point out that if
you put a Chevy engine(or any engine) in your car the TH350 tranny
fits nicely. The TH400 and TH700-R4 require a slightly shorter drive
for any Olds
Upgrading the ignition to something
such as the MSD 6A ignition and Blaster II coil will make your car
start easier and increase power in the upper RPM bands. It would
also be a good time to upgrade your plug wires too when upgrading
One other upgrade that is often overlooked
at first is the gears in your rear-end. These are the factory specs:
stock 307 3spd - 2.14, stock 307 4spdO/D - 2.56 or 3.08, stock 231
3spd 2.41, stock H/O & 442 - 3.73. The H/O and 442 rear-ends
are 8.5" while the rest are 7.5". Those of you with a
3spd tranny could move up to 3.08's and you O/D tranny owners can
move up to 3.42's. When replacing, I recommed finding a rear-end
from a H/O, 442, or 84-87 Turbo Regal. The H/O and 442 rear-ends
are 3.73's while the Turbo Regals are 3.42. All three are 8.5".
Monte Carlo SS's had 3.42's in early models and 3.73's in later
ones but are 7.5" rear-ends. They will work but aren't as strong
as 8.5". Keep in mind that shorter rear gears will have your
car running at higher RPM's.
To compensate for the higher RPM's
from that new rear-end, replace the stock 14x6 wheels with 15x7's.
These larger wheels will also improve the car's handling. Aluminum
wheels are light, but can easily be bent or warped. Those looking
for 442 or H/O wheels may have some difficulty. They are kinda rare
and most people keep them on their car. Coker
Tire sells reproduction rims (Chrome SSII) that look like the
H/O and 442 wheels but without the ardent or gold accents/stripe.
Last I checked they were $520 + shipping for 4 wheels.
Those of you with the 200-C 3spd tranny might want
to look at moving to a 200-R4 4spd O/D tranny. If you can can find
a used one from a H/O, 442, Monte SS, or 84-87 Turbo Regal that
would be best as they were stronger than a 200-R4 on base models.
The 200-R4 is geared better and is more durable than a 200-C. It
also gives you better gas mileage because of the overdrive. One
thing I will caution though is if you couple an O/D tranny with
your stock 2.14 gears (307 Y owners), the car will really bog down
when cruising at lower speeds.
Functional Ram Air: Adding
functional Ram Air (cold air induction) will help feed cooler denser
air to the engine making more power. You won't believe how easy
it is to set up! Here is MY Ram Air/Cold Air Induction page with
a few variations to choose from. -Here
(off site) is the link to the original page that shows how to make
your own. Its shown on an Olds 307 but it should work on the Buick
231 as well.