63 vette heads

[Robert M.]

What does the "humps" on the front of the heads look like on a 1963 327/250hp. The heads on the car have a rectangle bump with a triangle bump above.

[Craig S.]

Re: 63 vette heads

Keith - this are not the correct heads, they are later vintage (at least in the late 60's to mid 70's). The famous double hump have rounded humps. The rect/triangle you describe sounds similar to what are on a 74 I have.

[Joe L.]

Re: 63 vette heads

Keith-----

The identifying symbol on the ends of the cylinder head that you've described is the correct symbol for the 1963 250 hp 327 heads. The casting number, found under the valve cover, for these heads is 3795896. That's important, too, because the same casting symbol was used on cylinder heads of other casting numbers.

[Craig S.]

Re: 63 vette heads - MY error

Keith - sorry for the misinformation- I see Joe clarified for you. I was assuming the double hump were correct for 63 similar to my 67, sorry for the incorrect input!......Craig

[Harry Sadlock]

Re: 63 vette heads

Keith, the rectangle bump with a triangle bump are 250hp heads. Pull a valve cover and check the part number and the cast date. If you look on ebay they are often called Power Pack heads.

Harry

[Tom D.]

Re: 63 vette heads

The "power pack" head symbol goes way back. Alan Colvin's books detail the various such "marks" quite well.

I have photos of a 1960 head with the same type of symbol on www.midvette.homestead.com (Click on the word heads after you go there).

Tom
4889




MichiganNCRS.org

[Duke W.]

Re: 63 vette heads

Those 896 head castings were pretty long in the tooth by '62, but they kept using them for the 327/250. All the other 327s used the "big port, big valve" 461 or 461X castings.

My understanding is that the '65 327/250 actually used 461 heads, but they kept the power rating at 250, and with the smallish 400 CFM WCFB, it was carburetor restricted with the "big" heads.

For '66 they finally put the 327/250 out to pasture and made the 327/300 standard.

Duke

[Charles M.]

Re: 63 vette heads

I have a head guide in html format I would be happy to send to you. It shows the various humps. If interested drop me a line with your e-mail address. Chuck - 64vette@tampabay.rr.com

[Gordon Peterson #4961]

Re: 63 vette heads

Duke, your comment reminds me, I've been meaning to ask someone. What is the significance of the X on the bottom of the 461X heads? Thanks.

Pete

[Duke W.]

Re: 63 vette heads

They're supposed have a bit more port volume - about 175 versus 160 cc, and the additional 15cc is in the bowl area above the valve.

I've never seen any comparative flow data either as OE machined or with hand reworking.

Duke

[Mike M.]

Re: 63 vette heads

Is there any evidence of the 250hp engine using the 461 heads in '64? I know the '65's came with 461's and WCFB's. I worked on too many of those.

Mike

[Duke W.]

Re: 63 vette heads

Not that I'm aware of.

Duke