[idaho2some]

We have a 67 Pontiac Lemans with the original 326, 2BBL carb engine. It's got well in excess of 100,000 miles on it, it's tired, and time for a rebuild. It heads into the shop on Monday to start the process. The car also has a rebuilt Super Turbine 300 (ST-300) two speed transmission in it. It is our intention to retain this transmission. We're thinking this might be a good time to change out some of the OEM equipment for a bit of aftermarket that will give us a small performance increase in terms of low RPM throttle response up through about 5500 RPM. We'll save the OEM parts in case we ever sell it they can go into the trunk. I'm looking for opinions here. Thinking about a good set of headers (probably about 1-3/4" primaries), maybe going with a slightly more aggressive cam, and changing it over to a new dual plane intake with a four barrel carb. Companies such as Edelbrock seem to carry "packages" such as their Performer-Plus cams, along with Performer Series Intakes and Carbs. Approaching it this way seems like a good way to ensure everything fits and functions well together. Thoughts?

[LATECH]

If you are going to the trouble to retain stock 326, and are concerned with appearance, then look for a square bore 4 bbl intake (Pontiac) and run an AFB (factory) on it. They used that on the 326 HO in 65 -67 ,IIRC . Be aware that 64 heads are a tad different then 65-71, as are 72-79.
Be sure to get the corret intake for the year block/heads you have.
Headers would be an improvement, just don't go to large on the pipes, 1 5/8 or 1 3/4 would be fine. Also don't put a 3 inch exhaust on it. Use a 2 or 2 and 1/4 . 2 1/2 at the
most.Too big will lose performance.
Check your compresson ratio before choosing cam.Dont forget to calculate engine RPM at cruise...65 MPH also. Tire size gear ratio, vehicle weight and intended purpose all comes into play when choosing a cam.
something like a comp cams 51-221-4 mat be about right for you . CC those heads.If they are at 62 CC that would make your static 9.2 to 1.might be a good combo.

[RamAirIV28]

I would look at the HO 326 stuff for a start and maybe upgrade to 68 350 HO stuff, like a q jet, cam as well as your headers. maybe a th 350

[helmerrock]

A Summit 2800 would be a good cam for that motor.

[geeteeohguy]

You can do one modification that is invisible that will feel like your car has 100 more horsepower. With no engine mods at all. Simply replacing the 2 speed auto trans you have (that has a 1.76 low gear) with a bolt in TH350 or 200r4 will give you a TON of power off the line (2.75 low gear and better). It will literally change the entire car. If you get a 200r4, it will have overdrive, too. Better still, it is undetectable. Then, if you want, add a 4bbl intake, a decent cam, and a decent set of exhaust manifolds, and you'll have quick, economical, and fun to drive cruiser. Seriously, those St300's are bulletproof, but they turn an otherwise peppy car into a dog.

[LATECH]

Originally Posted by geeteeohguy

You can do one modification that is invisible that will feel like your car has 100 more horsepower. With no engine mods at all. Simply replacing the 2 speed auto trans you have (that has a 1.76 low gear) with a bolt in TH350 or 200r4 will give you a TON of power off the line (2.75 low gear and better). It will literally change the entire car. If you get a 200r4, it will have overdrive, too. Better still, it is undetectable. Then, if you want, add a 4bbl intake, a decent cam, and a decent set of exhaust manifolds, and you'll have quick, economical, and fun to drive cruiser. Seriously, those St300's are bulletproof, but they turn an otherwise peppy car into a dog.

X2 .The t 350 will make a big improvement in performance.The 2004r will really make a lot too.and as stated overdrive.

[b-man]

The Edelbrock Performer would be the perfect intake for a hopped-up 326. It has smaller runners than a '67 and up Q-jet intake that will promote good low-end and mid-range performance, but plenty of cross sectional area in the runners for good top-end as well.

It would also enable you to run any carb you want as it accepts both square-bore (Holley) and spread-bore (Q-jet) carbs.

Originally Posted by helmerrock

A Summit 2800 would be a good cam for that motor.

Agreed, essentially the same grind as the Edelbrock Performer cam.

I'd pass on the Edelbrock carb, there are much better alternatives out there. I'd put a Q-jet on it if it were my engine.

[Squidward]

I likes 2800 cam and TH350 too! I'm not sure about headers tho. I would question what small performance gain vs. PITA factor. Probably better to stick with iron exhaust and duals unless you plan on going significantly deeper in your quest for power.

[Jerry H.]

I've run the '068' cam with great results in a 326; along with a factory 4bbl intake and Pontiac AFB carb with dual exhaust. Personally I would go with Ram Air exhaust manifolds instead of headers. They will NEVER wear out and look more like stock. Good luck. I'm with others about the ST 300. A good upgrade would be a TCI Streetfighter Turbo 350.

[jonmachota78]

i agree with b-man in the intake. I ran consistant 13.1 in the quarter with an unported performer intake and q-jet on a 406, so I'm sure it will support a healthy 326. You may not gain with headers. Could be a big hassle just to loose power where you want it. If you must go the header route, I'd go no bigger than the 1 5/8" primaries. I think you would loose too much torque with the 1 3/4" primaries. Lots to gain with a good timing curve and dialed in carburator.

[PONTIAC DUDE]

Originally Posted by idaho2some

We have a 67 Pontiac Lemans with the original 326, 2BBL carb engine. It's got well in excess of 100,000 miles on it, it's tired, and time for a rebuild. It heads into the shop on Monday to start the process. The car also has a rebuilt Super Turbine 300 (ST-300) two speed transmission in it. It is our intention to retain this transmission. We're thinking this might be a good time to change out some of the OEM equipment for a bit of aftermarket that will give us a small performance increase in terms of low RPM throttle response up through about 5500 RPM. We'll save the OEM parts in case we ever sell it they can go into the trunk. I'm looking for opinions here. Thinking about a good set of headers (probably about 1-3/4" primaries), maybe going with a slightly more aggressive cam, and changing it over to a new dual plane intake with a four barrel carb. Companies such as Edelbrock seem to carry "packages" such as their Performer-Plus cams, along with Performer Series Intakes and Carbs. Approaching it this way seems like a good way to ensure everything fits and functions well together. Thoughts?

Sometimes those "packages" are for a certain combo and never really worked out for that model engine or even brand. They do the Chevy and then use roughly the same specs for a Pontiac, Buick, Olds, etc. .

[dmac]

326 doesn't move as much air as a bigger motor. Either keep your stock exhaust or go with aftermarket version of Ram Air exhaust manifolds. Headers on a 326 aren't worth the trouble, go with dual exhaust with crossover, ot X-pipe.

You might be able to get away with a big 2 barrel carb on your current intake- just an idea others might be able to expand on. Explore that option. I know there are 2 barrels rated at over 500 cfm, but the rating system is supposed to be different for two barrel?????

Upgrade the cam but not so much you need to modify the heads except for maybe elongating the pushrod holes to use higher ratio rockers. Higher ratio rockers allow you to get more duration/lift from a slower ramp cam that is easier on cam/lifters with todays cam lobe profiles.

Save your bucks for the tranny swap. I swapped from the two speed to a T400- huge difference in a 68 lemans with a 350 motor. I will likely never buy headers again unless I am going for all out power due to the hassle of just the install.