Heads 64cc 1.94 in. and 1.5 ex. valve hump heads on the 275 and 76cc 1.72in valve heads on the 210.

 

210hp/327 = small valve heads and 8.75 to 1 CR..

275hp/327 = medium valve heads and 10.25 to 1 CR.

The only difference that guys say between the 275hp and 300hp/327's was the 300 ran duals and had a good cast-iron, AFB intake on it. I have one of 300hp's intake's up on the shelf now.

GOOD old STOCK cast-iron 4-barrel intake!!

Same cam..

And I have NO idea what the 250hp/327's spec's are??

pdq67

 

Yes

The 275 horse in 1966 used the '461 head casting, which is the 1.94"/1.5" 62 cc chamber fuelly head. For '67 the 275 horse used head casting number '291 with the same specs except the combustion chamber lists as 63 cc instead of 62 cc. The 275 used four eyebrow cast flat top pistons, and it had a different distributor number 1111152, but it used the same cam casting number 3896930 as the 210 (specs are 0.390"/0.410" 310°/320° duration with hydraulic lifters and stamped 1.5:1 rockers).

The 210 horse 327 used the '775 casting with 1.72" intakes and 1.5" exhausts with a 74.6 cc chamber. These heads have two square humps instead of the rounded camel humps of the fuel head. The 210 used the same four eyebrow cast flat top pistons, and it used distributor number 1111150. As mentioned above the cam was the same on both engines; so basically it is the same short block with different heads and distributor. The 275 used a Carter AVS four barrel (a Holley 4160 was optional) and the 210 horse used he Rochester 2G two barrel carb.


Larger Dave

 

The 67 275hp used a quadrajet.The 250hp was a 210 with a qjet.

 

Plum,

My book says the 250hp/327 is a 10.5 to 1 CR. engine??

pdq67

 

Same flat top piston, different sized combustion chamber head, for different static compression ratio.

When book (Covan) called out Carter for carb I jumped to the wrong conclusion, as I had forgotten about the Carter Quadrajet built under license. The 283/195 horse; 327/210-275-300 horse; and the 350/295 horse engine all shared the same hydraulic flat tappet cam. The 327/350 horse used a hotter flat tappet hydraulic cam; and the 327/365-375 horse engine used the same flat tappet solid cam as the 302/290 horse engine.


Larger Dave

 

That is a big difference in CR. What was the difference in the pistons to cause that.

 

Same pistons flat top 4 valve relief difference was 75cc vs 64cc chamber heads.

 

Yep!

the old -929, the -151 and the 30-30 solid or -346 cams in that order.

pdq67

 

PDQ I had a 327 250hp out of a Chevelle never been apart and it had the 75cc heads with a qjet.

 

Thanks, like I said, I had no idea what a 250hp/327 was made out of.

pdq67

 

I have the 64cc double humps on mine with those flat top pistons. How high would my compression go if I put some of those keith black domed pistons. Yikes I hope not too high.

 

A stock type K/B domed piston with double-humps should be right around 11 to 1 CR.

BUT they also had taller, stock type domed pistons back then that made 12.5 to 1 CR too......

I think some guys just machined the taller domes down to get the CR. they wanted back then. Heavy pistons too..

pdq67

 

The 327/250hp is not a 210 hp. The 250 hp used a 870 blk. Power pack heads with a small runner cast iron intake and a rochester 4gc carb and a slightly milder hyd. cam than the 300hp. engine. The 870 block was only used from 62-65....

Also the 327/275 hp did NOT always come with a Q-Jet. I have seen then commonly with a carter AVS and on some Chevelle wagon applications with A/C I have seen a 585 holley...

 

Maybe the problem is there was more than one 250hp 327.The one I had was from a 68 Chevelle it had the same heads as the 210 hp engine with a Qjet.

 

'65 was the last year Chevy used Carter carbs (WCFB's on 327/250hp, AFB's on 327/300hp).

:beers:

 

John,

Would you please spec the 250hp/327 completely..

Thanks,

I ask this b/c my long gone Blacksmith Buddy's Son had a NEW gold painted '63, 300hp/327 Imp., H/T, P/G car back then and I never knew the difference between it and the 250hp car??

Sucker would run like the wind just like my RR Buddy's black painted, '64 Imp, 300hp/327, 4-speed H/T. The one we got nailed at like 120 or so coming into Knoxville, IA from the west Friday noon coming home to Missouri back about the spring of '67!!

pdq67

PS., AND I know I'm NOT suposed to bring this up, but I just wished that the young-un's were able to drive like we did back then b/c it wasn't nothing to hit 110 up to 125 mph for miles and miles b/c there flat wasn't much traffic on the road in the country between country towns AND the MAN had to catch you!!

AND myself, Gary and Jim were young and were going to live forever!!

 

John Z
There was NEVER a carter wcfb on a 250hp 327. They were all Rochester carbs. The BEST place to find the truth about combinations and what was or is availible today is to contact NHRA for their technical data sheets. I have been racing stockers and super stockers for the past 36 years and have a pretty good handle on what was produced....Especially Chevrolet.

 

Nope. 327/250hp Corvettes used a WCFB from '62-'65; there were no Rochester carbs on Corvettes until 1968. Been restoring them for 40 years. :thumbsup:

 

I thought a WCFB was a Rochester, pre Q-Jet!!

And I've had two of them way back there, one on my '57 and one my Mom made me remove from her new '65 195hp/283 2-barrel Chevelle.....

Boy, did she get hot over that 2 to a 4-barrel swap!!

pdq67

 

I thought a WCFB was a Rochester, pre Q-Jet!!

pdq67

The Rochester predecessor to the Q-Jet was called the "4-Jet". :thumbsup:

 

JohnZ
So you are telling me the 64 Vette Coupe I own that is a 250hp 327. With a glide,a/c,p/s,p/b and p/w with a rochester does not exist? This car was bought new by a family member and has never been changed mechanically. Also this car is the most rare of 64 Vettes produced.You should automatically know that by restoring them for 40 years!


PDQ.....its called a carter wcfb. First used in 1955 on the 265 engine. You could also get the 2x4 version. With a solid lifter cam and also a hyd. lifter cam. Maybe the 40 yr. Vette restoration guy can tell you the hp of both engines I already know! You could also get the same option on the 57 283. It was a 270 hp and a 245 hp. The 270 hp solid lifter cam was also the same used in the 283hp. Fuel Injection engine.... Some people get the rochester 4gc confused with a carter wcfb as the two resenble each other a little. LOL Maybe the Vette guy can tell you the difference by just looking at the top of the two carbs. Both were also different CFM carbs.

 

JohnZ
So you are telling me the 64 Vette Coupe I own that is a 250hp 327. With a glide,a/c,p/s,p/b and p/w with a rochester does not exist? This car was bought new by a family member and has never been changed mechanically. Also this car is the most rare of 64 Vettes produced.You should automatically know that by restoring them for 40 years!

Yup, that's what I'm telling you - that '64 was built originally with a Carter WCFB #3696S, GM #3846246, on an iron intake, casting #3844457; there were no Rochester carbs of any kind on any Corvette until 1968 (first Corvette usage of a Q-Jet).

There were 3,262 250hp Corvettes built in '64 (out of 22,229 total), and 904 of those 3,262 had Powerglide. :thumbsup:

Here's one of my 2x4 setups (this is a '58); WCFB's were rated at 390 CFM.

:beers:

 

Hey John Didn't a 66 Chevelle with a 327 come with a Carter? I can recall I thought my 66 had one but that was 35 years ago so I could be wrong.

 

MY BAD!!

Carter WCFB and it had a cast-iron base plate.. It pre-dates the aluminum Carter AFB...

Rochesters are the 4G and 4GC before the Q-Jet..

Sorry guys, I'm learning this again b/c it's been too many years.

And I had a great big Ford Autolite off my Buddy's '58, 430 Merc. that I swore was a 780 Holley until I had it off and looked real close at it..

Again, my bad and sorry for any confusion..

pdq67