I have the opportunity to get a 327 or a 350 for really cheap (both need rebuilding). I will put either in my 84', probably late next fall or as a winter project. Which would be better? All opinions appreciated.
I am currently going to rebuild my 305 to L69 spec, and keep it as a numbers matching spare, or drop it into the ole' truck.

The new block will be coupled to a 5 speed (factory).

 

Always go bigger cubes. Especially if your gonna rebuild.

 

350

 

I so like polls... 350.

 

Damn, I am not getting suckered into this crap again. I am going to just let this all out in one post and leave it alone.


#1. 327 does not "rev" any better than a 350. The ability to rev high is controlled in the valvetrain on a SBC, at least as far as a streetable motor is concerned.

#2 Why not get the extra cubes? More CI = More potential.

 

We need to find a good compilation of reasonings for the 350 vs 327 "debate" and make a sticky or something.

 

Well, I didn't even think you'd need to ask yourself this if both need a rebuild. I could understand if the 327 was ready to go in and the 350 would NEED a rebuild. But hell man, go bigger, they both fit the same.


#1. Rule

No replacement for displacement.

 

Sounds good to me. But of course, someone would come in and start a new thread without reading it anyway. A simple search would have yielded at least 10 threads on the subject.

 

Yea, but then we can just say "hey, refer to this post here" and it may, just may, cut down on the disputing in that actual thread.

 

Sounds good to me, so who is going to write it up, and who will sticky it?

 

327, specifically small journal forged steel crank 327.
The problem is there are none of these left that haven't been bored to the water jacket and had the crank ground to dust.
(never say never I located 3-count'em 3, DZ 302 sbc's up in Ga.)
By the way, good idea on the 327-350 debate,thread too bad it got locked.

 

Here's a DD graph that shows the power curves of the 327, 350, 383, and 400.
All using the XR-274 cam, and 195cc heads.

https://www.thirdgen.org/techbb2/att...postid=2072263

As has been mentioned earlier, and I'll agree with. If a builder is starting with a clean slate, more displacement seems to make the most sense.
But as the owner of a 327 that I'm building because I already had the parts...
Well, I'm not gonna cry in my beer cause I wish I had more low end torque. I'll just spin it faster and have fun with it.

 

327 vs 350

350 4.000 X 3.48
327 4.000 X 3.25
302 4.000 X 3.00

they all use the same 4.000 010 casting block till late model. Any one of them can be turned in the other with the right piston/crank

Its an "old timers tale" based on the tune of 60's 327's compared to the tune of late 70's 350's As the fuel & emmision crisis developed in the early seventies horsepower dissappeared. 350's were being phased in and 327's were being phased out. A 67 327 made alot more power than a 76 350. The 350 was labeled as low performance motor as a result. These people did not seem to remember the 70.5 350 375HP LT1. This was chevy's most powerful small block ever up until GEN II LT4. Maybe even later since US car were rated conservatively then as there was an insurance crisis to go along with this era.

1972 US OEM's changed to SAE NET HP ratings from GROSS HP ratings lowering numbers roughly 20%.

"but 327's really rev" No kidding! they had bigger cams & intake systems compared to later emmisions motors.

In truth 327's do have higher peak power RPM, just like 350's have a higher peak power RPM than 383's do. The smaller engines do not have more power just peak at a later RPM with same cam/head/intake etc. (bore/stroke & rod ratios are beyond the scope of this simple explanation and are miniscule in comparision to displacement)

I can think of only 2 reasons to build/use a 327

1. Numbers matching restoration
2. You already have one and its not wore out yet

The next time you hear this tale try to snub it

Bye for now

Todd

 

I actually have the thread written, if you search for 327 350, facts and myths, you will find it.

I have some dyno graphs that still need to be added to it, I guess I need to PM five7 so I can get it unlocked to put it on.

 

You still haven't gotten around on that LJ? Shame on you.

 

I pretty well have it all ready, I am going to PM Five7 tomorrow, see about getting it unlocked for me to put them up, with explanations.

 

Ah ok. Are these the graphs we worked out or did you tweak up some others?

 

They don't use the same block all of the way through, the early 4in bore block is for small journal forged crank 327's (and 302's), They didn't start running the big journal (mostly cast) crank until 69 maybe late 68. I remember when the 350's came out we though they were turds compared to the 327's, at least until the LT-1's showed up about 1970. Maybe the 327 revving thing is a myth to some of you, but in 72 Grumpy Jenkins picked the small journal 331 to kick the living crap out of the Chrysler Hemis in Pro stock... and he could've picked a 350 if wanted to.

 

I'm going to "stick" it over on the Engine Swap forum. I'll unlock for you to post there.