five7kid

That's not surprising, as it was a run-of-the-mill 4" bore block, used for 327's and 350's.

86 sports coupe

If it is a 69 block it wouldnt be the same casing as a 327, maybe a 350 but not a 327. GM never made a 4 bolt 327. Im sure there are alot of 4 bolt 327s on the streets, but gm never made them.

Apeiron

Who said anything about 4 bolts?

The 3932386, 3970010 and 3956618 castings were finished for 4 bolts in the Z-28 302, and 2 bolts for the 327.

86 sports coupe

read the last coment before mine, it mentioned the possibility of using a 302/327/350 block for a 4 inch bore. In 69 the 302/350 went 4 bolt.
I dont know everything and Im not pretending to.
SO IF EVERYONE KNOWS EVERYTHING ABOUT THE SMALL BLOCK CHEVY, WHO DESIGNED IT? I know, I want to hear what people think designed it.

Apeiron

Yes, and the same castings were used for a 302, 350 and 327, regardless of whether they were later machined for 2 bolt or 4 bolt caps. It's entirely possible that a 327 could have the same casting as a 302.

87z28fromhell

This NOM that I have was one of three that were supposed to be used for testing at the factory which was Bohn aluminum. Two of them were actually used but this one was never fired. Yes the 327 was never "released" from the factory with four bolt mains, that is not to say that they weren't tested with four bolt mains. I have not had the oil pan off to see if the engine has two or four. My grandfather said that he thought it might have been a four bolt main engine, but it is definitely a 69 327 with a steel crank, double roller timing chain and had the small valves which it was intended for heavy truck or industrial use. An interesting side note is that the 1969 c-10 and c-20 no longer had the option of the 327. Anyone have any reason or theory why? peace out.

86 sports coupe

My guess would be that after 67 chevy released the 350 acrossed the board in just about anything with an optional v8.

87z28fromhell

thanks for the guess, however the two small block options in terms of cubic inches for the 1969 c10 and c20 were the 350 and the 307. I just find it strange that you could get a 327 in a camaro, among other vehicles, in 1969 but not in a truck.

86 sports coupe

maybe they were phasing out the 327, and didnt want to cast more 327 parts than they had to?

Rockin-Iroc

I find it hard to believe the tuned port 350 never found its way into a truck. That would have made a very torquey truck motor. In fact, I'm also surprised that a Chevy 400 never ended up in a production Corvette. They did put one into a show Corvette but never into a production Corvette.

And regarding an earlier comment, I'm pretty certain Corvette small blocks were typically always 4-bolt mains, and that includes 327's. The moderator is right, there were two different main bearing sizes for the 327, small and large. So not all 327's are compatible with different stroke cranks.

For example, if you have an earlier 327 with the small journal crank, you can build a 302, but not a 350. If you have a later 327, you can build a 350 or a 383. While we're at it, you can destroke a 400 to make it a 377 and it would have about the same rod/stroke ratio as a 327 except with 50 more cubic inches. But in order to do that, you have to modify a 350 crank shaft for the 400's journal size. That makes a really nice race motor that loves to rev, but I would put a large single carb on it with a single plane intake to better take advantage of the high rpm talent.

There are a lot of combinations you can do with the gen II small block. It's when you get into the LT-1's and later that you can't swap things around anymore.

There are many great heads you can get for the gen II's. Probably the most powerful head I know of is a 4-valve/cylinder head for the Chevy small block made by Dominion. It is still a pushrod design, it just has shaft mounted custom rockers to push on 2 valves each rather than one. I remember an article years ago testing the Dominions against the best 2-valve heads and the Dominion heads were an honest 100 hp stronger. They were about the same up to around 3500 rpm, and then the 4-valve heads made better power above that as if there were a supercharger bolted on. When I priced them, the bare heads were 5 grand and built up, they cost 7 grand. So if money were no object, these are the heads to have. I did a search yesterday and found them still available through GMPP.

__________________
1986 IROC-Z
Tuned Port 355, 10:1, 350hp/400 lb-ft

1968 Corvette Convertible
630hp/600lb-ft 427 BBC

1968 Pontiac Firebird
500hp/522lb-ft 465 Poncho

NHRA427

The 2 different main journals on the 327 is correct. The 67 350 had small journals also. In 68 both 327 and 350 went to large journals. 327s only had 2 bolt journals. Most older guys will say that the small journal 327s ran better then the large. When I build 400s I turn the shaft down to the 350 size and use special bearings. learned our lessons on circle track cars that the huge journals on the 400s don't like rpms. once we went to the smaller journals the engines lived for 5 years with a lot of abuse. There are so many combinations with small blocks you can make almost anything all it takes is turning shafts down or special bearings, or boring out the block. 307 bored to 4in is a 350, 283 bored to 4in is a 302 and so on. I like to build street engines with less low end. Every engine i have had could smoke the tires. I like the engine to make more power once the car is rolling. But thats just me.

86 sports coupe

the 307 and the 283 has the same bore, if you bore a 307 to 4 inch bore( wich the block will not take that bore) it will be a 327, look at the stroke of the 327 and 307 you will find they have a 3.25 inch stroke.
There is some truth to the smaller journal engines revving faster, I beleive there is less friction do to the smaller journals.

five7kid

It has to do with bearing speed - the linear speed between the journal and the bearing. The bigger the bearing, the higher the linear speed, the quicker you'll shear off the oil.

NHRA427

Sorry about that mistake on the 307 your right bored to 4in is a 327. Those blocks will go to 4in. have done alot of them and used 350 shafts to make cheap 350s when the 350 block was cracked. Never once had a problem. My uncle in the 60s before chevy built a 302 was boring his 283s out to 4in and running them in his C-gas dragster.

ljnowell

How far over would it have to go? .120? I dont think I have ever seen any production SBC that would take an overbore like that. I have heard lots of rumors over the years about special 283 blocks that would take a big overbore, but like all urban myths, I have never seen one, or knew someone that has seen one, in person.

Looks like the whole purpose of this thread was pretty well missed. Lots of bickering about high revving this and that. Oh well, at least its all here, and not all over the rest of the boards.

tom3

Pretty common back in the late 50s and into the 60s to overbore a 283 what was called a 301. I remember even Sears sold domed pistons for that .120 overbore. Those engines would run with the Duntov cam, better with a Crane. Some of them didn't run too long though. I've always thought the 327 was the best all around (real) small block built. These new roller cam engines are a whole different breed though, and probably way ahead of the older engines.

90Formula305

I still prefer the 327

ljnowell

Care to eleaborate? Just dont give us more of the High Revvin', totally different sound, 10K RPM, kill any 350 stuff.

90Formula305

When my dad was still racing he had a cj-5 with a 327 in it. raced for 2 years with same motor in it, consistently hitting 7500+ rpms with it and it never died, after he was done racing he took that motor out and put it in his '55 chevy pickup. Use to mud bog that thing all the time, i have a picture in a frame of him running through a mud pit at WOT in 2nd gear at 7800. Had to get rid of that stuff when i was born though. So reliability would be the big thing for me, plus the surprise on peoples faces when you tell them it's a small journal 327. He put a .600 lift cam in it, so people would ask him all the time if it was a big block. That was way back in the day though, before everybody forgot the terms small and big block. Except one kid i know says that an s2000 has a "big block 4 cylinder".

ljnowell

If the engine in question was attaining those RPM's it had massive valvetrain upgrades. If those same parts were used in the building of the 350, it would do just as well. The engine didnt perform well because it was a 327, just because it had a proper valvetrain.

90Formula305

Does everything that everyone says have a negative reply from someone else? It's just from what ive had expierience with, what ive heard, etc.. I just prefer the 327, im not saying i wouldnt take a 350, i have a 4 bolt block sitting in my garage. But i would build the 327 first. Who has a 327 now? not many people, just to be different is why.

five7kid

The title of this thread is "327-350 Fact from Fiction". The intent is to provide technical facts to dispel the many myths surrounding this historical engine.

For whatever reason, people forget the historical part and go straight to hysterical. When asked why you said you prefer a 327, you talked as if the reason the engine your dad had could do all those things was because it was a 327. The response to that merely pointed out that being a 327 was not why it could do the things it could do.

Being "different" is the #1 reason why people say they want to build a 327/302/335 etc., etc., etc. Fact is - you're the only one who will know it is "different".

90Formula305

So pretty much everyone on here hates the 327? Thats pretty ****ing lame. Not everyone has a built 350 in your town, my town or their town. So when you have a 327 and you kicks someones *** with it and then you tell them it's a 327, now your different. The automatic assumption now is that everyone has a 350.

stinger74

I have a 327 currently in my 63 Impala station wagon. It's sound is better and with the 4.11 posi rear I needed something to make the power quicker and I didn't need the extra torque. As far as RPM, I've taken several 327's to 7 grand on multiple occasions and they've stood up. In '68, the reason the large journal 327's sucked is because of the heads. Take an early 327 and a 350 and slap Vortec heads on them and you'll like the power ratings on both motors. 327's require higher gears for heavy vehicles. It's all about what you need from your motor.
As far as the moderator starting the thread off by telling people "This is not about who's right or wrong" and then bashing people and telling them they're wrong constantly, well that's why I don't visit this site much. If I wanted to talk to @$$holes, I'd talk to my in-laws.

90Formula305

Yeah its been a few months since i posted here too.

ljnowell

I dont understand, you seem to be contradicting yourself. If you wanted something that would make the power quicker, why did you use a 327? Just because you have taken several 327's to 7 grand doesnt matter. I have taken several 350's to that also, including the one in my car now. Your post has absolutely no point, other than saying that you built an engine that made less power than a 350, because you didnt need it.

Thanks for the compliment, we like insults! Especially from people such as yourself.

90Formula305

What exactly do you have against the motor? Did a 327 stuff you in a locker or give you a wedgie in high school ? It's just a personal preferance man, take a chill pill! You like your 350, myself and other people like the 327, not saying i wouldnt build a 350 but you know what i would build first.

ljnowell

Dont you get it, you are in the wrong thread then! This thread is not about what Ilike the most, or what my preference is. This thread is about documented proof and facts relating to the two engines to give a valid comparison.

Apparently you are too dense to figure that out. That was also what the mod was "acting like a mother in law" about. YOU are posting in the wrong place.

stinger74

Documented proof is that I've owned a lot of both engines and I've always had better luck with the 327's. Personally, my preference is a big block, but you didn't want to hear about preferences, so I left that out. You seem to have no problem ripping people about their opinions and experience, but have a thin skin about your own opinions. I agree that a 350 is a good motor, why else would they have lasted so long? But then front wheel drive has lasted a long time too. Learn to keep an open mind and your tongue tied up in that piehole of yours and you might learn a thing or two. I'm old and I learn things every day.

ljnowell