this is my opinion. its hard to beat the cool factor of a tri power. but a 4 barrel intake is cheaper and will get you rolling and having fun. a edelbrock performer is a good intake and lighter but a factory will work just fine. unless the cam that's in it is worn i would just change the intake and carb. a 500 cfm or 600 cfm would work or a properly set up q-jet. in the end its your car and the decision is up to you. keep having fun man.
What can I do with my 326?
61 - 80 of 86 Posts
Oh I'm all out to impress EVERYONE! However, in the world of 700hp grocery-getters and photon speed lithium cars, my aspirations for "king of the road", have long gone. Nowadays, Im more of a slow cruise kinda guy, but I always find a way to let everyone know who's boss.Hmmmm. And wanting 2x4's on your engine build, is that to impress yourself, your passengers, and others?Hell ya, isn't that the ENTIRE reason we have Pontiacs in the first place, to IMPRESS the world - especially the chicks.
If you have not experienced mulitple carbs, you have not lived.
As for my dual quad dreams, if anyone here would do it, it would surely be me... but if they ever materialize, which isnt likely with pandemic pricing, it would be with ported heads and a big cam, on a 428!
Army: "the reason why I was trying to talk you out of it was your lack of cubes!"
PJ: Ya just gotta know old cars. Not a true statement above. Just check out these "lack of cubes", compression ratio and HP numbers. Let the HP/speed wars begin.
Corvette 283CI - Super Turbo Fire 9.5:1cr 245HP 2x4 carbs, 1.72/ 1.50-inch valves.
1956 Pontiac 316CI - Optional 10:1cr 285HP 2x4 carbs, 1.72/1.50-inch valves (Pontiac air cleaner like Caddy type)
1955 Cadillac 331CI - 9.0cr 270HP 2x4 carbs, 1.75/1.56 -inch valves
1957 Plymouth Fury 318CI- 9.25cr 290HP 2x4 carbs, 1.84/1.56 -inch valve
The only common Pontiac engine, which is different from the others, is the 301.
As you can see here, many or most of the Pontiac engines, are achieved by swapping cranks and blocks... For example, the 400 and 428 use the same bore, so if you had a 400, you could buy a 428 crank and it would then be a 428. Likewise, the 326, 350, 389, and 400 all have the same stroke, so it's (theoretically) possible to bore a 326 and make it a 400
You may have back peddled, but we NEVER EVER discourage souping up a Pontiac engine due to cubes - it can still be a Chevy or Ford stomper. Matching parts does it and if you look at the engines I pointed out, they are factory and no fancy porting, big valve heads, aluminum add-ons, roller cams/lifters, etc.. That was my point. It is the cam that would be the key, followed by a good exhaust system, and the tri-power would be at home. Simple build IF the 326CI now in the car is being enjoyed as is an a little extra punch meant a bigger smile.
Remember, matched parts also includes driveline. My guess is that a warmed over 326 with 4-speed and 4.88 gears will walk over a bigger cube 461 with TH-400 and 3.08's.
No, you can't buy a 428 crank and drop it in a 400CI. Pontiac does not have a small or big block BUT, they are viewed by the mains on the crank, 3.00" vs 3.25" and the crankshaft thrust surface is different.
You are not going to bore a 326 over to make a 400 bore. If you went .060" over on the bore, you would get 3.750". You aren't going to bore the cylinders .400" to get a 400CI bore size or you will be hitting water for sure.
You could however use the 326 crank in any of the 3.00" engines. BUT, the 326 & 350 crank have smaller crank weights, so an engine using one of these typically has to have the crankshaft balanced using "heavy metal."
From PY, Here are the results:
- late 1976-up 350 #496452 - 64 lbs
- 1966-67 326 #9782770 - 65 lbs
- 71-74 350/400 #4813 - 65lbs
- 68 350 #9793573 - 66 lbs
- 67-68 400 #9773524 - 67 lbs
- 64-65 389 #9773383 - 70 lbs
- 70-74 455 #9799103 - 71 lbs
- #9799103 - 67 lbs 455 (cut down for 3" mains and balance for light rod and piston combo)
- 301 crank 42 lbs
Lesson over.
Yes. I was paraphrasing. That's why I said "theoretically possible". I was more trying to explain the math behind the engines, because this certainly didnt seem like the kind of thread where anyone would actually try any of this.No, you can't buy a 428 crank and drop it in a 400CI. Pontiac does not have a small or big block BUT, they are viewed by the mains on the crank, 3.00" vs 3.25" and the crankshaft thrust surface is different.
You are not going to bore a 326 over to make a 400 bore. If you went .060" over on the bore, you would get 3.750". You aren't going to bore the cylinders .400" to get a 400CI bore size or you will be hitting water for sure.
You could however use the 326 crank in any of the 3.00" engines. BUT, the 326 & 350 crank have smaller crank weights, so an engine using one of these typically has to have the crankshaft balanced using "heavy metal."
From PY, Here are the results:
- late 1976-up 350 #496452 - 64 lbs
- 1966-67 326 #9782770 - 65 lbs
- 71-74 350/400 #4813 - 65lbs
- 68 350 #9793573 - 66 lbs
- 67-68 400 #9773524 - 67 lbs
- 64-65 389 #9773383 - 70 lbs
- 70-74 455 #9799103 - 71 lbs
- #9799103 - 67 lbs 455 (cut down for 3" mains and balance for light rod and piston combo)
- 301 crank 42 lbs
Lesson over.
Pontiac advertisements claim that the 400 was a bored over 389, and I can't even see that being practical, but again, my point was merely that by changing bores and especially strokes, you could create most any Pontiac engine. Granted, a 455 crank wouldnt fit in a 400, but the 455 stroke in a 400, would certainly make a 455.
Not sure why manufacturers "ballpark" cubes, but it seems common practice on cars and cycles to do so. My Trans AM had a 5.7, which they listed as a 350 on some parts of the car, and a 348 on others.
"Paraphrasing" is the road to ........ If you paraphrase in some cases, this get picked up by a newbie, which many of us were at some point, and then it becomes a '"true" thought and statement as some newbie says you can put a 428 crank in a 400 and make it a 428. Kinda like when those same people call their Pontiac engines a small block or big block because they are familiar with other brands that do indeed offer small blocks and big blocks known by cubic inch size. So better to point out the main journal size and note that a "stroked" 400 crank of 4.00" and 428CI piston pin height would be the same cubic inch as a 428 because they share the same bore size.
Army - "Pontiac advertisements claim that the 400 was a bored over 389"
PJ - It was, sort of,.......at first. Look at the first photo. This is a 389 piston. Easy to tell from the valve relief pattern.
Now look at the second photo. What do you see? A 389 piston. Wrong. That is a factory 1967 400CI
using the #143 small valve closed chamber heads and found in the early 1967 full sized 2-Bbl cars. It has the same valve angle/spacing as the 389CI, BUT it has/is the new 400CI block and bore. So the statement that the 400CI was a bored over 389 comes from that engine. It was not a true overbored 389 block, but boring a 389 .060" over is the same bore size of the 400CI and you can use a 400CI piston as long as you use the matching heads with the upgraded valve angle/spacing. The later year 1967 heads, and the first open chamber heads, were the "061" heads. The GTO 067 heads were the big valve heads/screw-in studs with the revised valve angle/spacing, but still closed chamber.
So you can see that 1967 was a transition year for the 400CI engine for several reasons.
61 - 80 of 86 Posts
