1964 300

[skylarker]

if i were to take my 64 skylark high compression 300-4, and put the 2 barrel intake and carburator from the low compression 300, would i see a gain in fuel economy, or would i screw up the whole dynamics of the engine? i'm an old man not looking for speed.

[TexasJohn55]

Disclaimer: I have no first hand knowledge on your particular question. I am not "intimate" with the Buick 300.

Speaking here in generalities: Your driving habits probably have the greatest effect on your fuel mileage. Secondly a properly tuned engine, a good tight distributor with functional mechanical and vacuum advance AND a sound engine base(rings and valves) have a critical effect on "potential fuel mileage".

The carb question is a good one. I am not convinced the 2 bbl will inherently improve mileage but in my experience, it does give a better "driveability" experience with less throttle input to feel good doing normal in town driving. Now if you are a lead foot, it will naturally deliver less fuel under full throttle and hard driving, which may improve mileage over the 4 bbl.

Like Forest Gump says, "And that's all I have to say about that matter", or something similar.

Hopefully,More knowledgeable Buick folk will step in to help with your question.

[65specialconvert]

The 64 300-4 has aluminum heads & intake,any year 300-2 intake is cast iron,not compatible with the aluminum heads from what I've heard.

[Dr. Frankenbuick]

The 64 300-4 has aluminum heads & intake,any year 300-2 intake is cast iron,not compatible with the aluminum heads from what I've heard.

Yes, the aluminum 64 heads and intake manifold have smaller ports then iron heads and intakes from 65-67. So, you can use an aluminum manifold (64) with iron heads (65+) as you go from smaller runners in the manifold to larger runners in the head. I had done this with my 300 with success to make my 67 a 4bbl. But, using the later iron intake (65+)on the early aluminum heads (64) will make a large runner intersect with a smaller runner. This will cause all kinds of turbulence in the intake where the two different size ports meet, and will eliminate any benefit of switching manifolds. The OP is stuck with using a 64 aluminum 2 bbl intake if he wants to make this change.

[bob k. mando]

The 64 300-4 has aluminum heads & intake,any year 300-2 intake is cast iron,not compatible with the aluminum heads from what I've heard.


concur, you would have to procure a 1964 aluminum 2 barrel intake to even bother with this switch.

if you're truly desperate to try a 2v carb, getting a 2v to 4v adapter plate will be much simpler. spacer plates ( which is what the adapter plate function as ) also tend to help the carb work better, you just have to make sure the cleaner still fits under the hood.


as said previously, the best ways to improve mileage are:
1 - give the engine a good tuneup, plugs, wires, carb reconditioning, etc. consider swapping in an HEI distributor from a 75-80 Buick 350, if sticking with the points distributor definitely recondition that.
2 - actual driving habits
3 - reduce gearing. you can achieve this simply by mounting larger diameter tires or you can change the rear gears in the car to a lower numerical ratio. aim the gearing for what you'd like your highway cruising rpm at your cruising speed to be ( 2500rpm @ 70mph, for instance ). changing the differential gearing / tire size will require a speedometer gear change or your indicated speed will no longer be correct.
4 - if you have an automatic trans, install a 200r4 ( overdrive ) or go to a manual transmission. there's more work involved in installing the manual but it's also far more efficient than any automatic.

[65specialconvert]

Did they even make an aluminum 300-2 intake in '64? I've never seen one & been a 300 guy since 1975.

[Dr. Frankenbuick]

Yes, there was a two barrel 300 aluminum manifold in 64 (KL and KM coded engines).


Sent from my iPhone using Tapatalk

[bob k. mando]

I've never seen one & been a 300 guy since 1975. *shrugs* how often do you see guys looking for LOWER performance? there's a two barrel ( one year only, 74 i think? ) 455 intake. i've never seen that either, but they're around.

[skylarker]

I have been driving the same 1969 converible for 33 years now. It came with a two barrel carburator and i drove it that way for many years before i changed out the egine and went with a mildly built four barrel. I think whoever wrote that buick only made a two barrel one year,, is mistaken. As for the 1964 skylark,,,it was offered with a six cylinder, a low copression two barrel, and a high compression four. I own one of low compressions, and two of the high compression 300's. I am not looking tolower performance as someone else suggested, i am simply trying to build a small block that is affordable to drive on a daily basis, instead of once a month or on special occasions,,,which is the case with the 69. So the question was, would the high compression engine run fine with a two barrel (which they make) and a two barrel carburator.

[bob k. mando]

I think whoever wrote that buick only made a two barrel one year,, is mistaken.


that's not what was meant. there were 2v 300s for every year the 300 was in production. there were even 2v 340s, although those intakes are wider than would fit on your engine. the 340 / 350 being a tall deck version of the 300 just as the 300 is a tall deck version of the 215.

what we're saying is that from 1965-67, all of those 300s have cast iron intakes and heads and do not match up well with the 1964 aluminum parts. being as the cast iron parts have larger intake runners, it's particularly bad to slap a cast iron intake on top of aluminum heads as you're going to create massive reversion steps for all cylinders doing that.

can you physically put a 2v 300ci cast iron intake onto 300ci aluminum heads? yes.

that doesn't make it a good idea.

the problem we're pointing out is that the specific year production of your engine creates swap problems what wouldn't exist if it were from 65-67.

unless you've got cast iron heads ( check with magnet ) for some reason, then you'll be fine with a cast iron intake.