1963-67 327/300 HP Head Info

[MoeJr]

Can anyone give me the info on the stock heads used on the 327/300hp engine from 63-67. I am looking for casting numbers and valve sizes along with chamber size. Thanks in advance.

 

[67HEAVEN]

Here's something to get you started.......

http://www.mortec.com/castnum.htm

 

[allcoupedup]

3782461 used from from '63 - '65 - 327/300 castings were machined for 1.94/1.5 valves. Some versions (SHP) were machined for 2.02/1.6 valves although most head shops have never seen them. the smaller valve configuration had 62 CC chambers and the larger valve config had 64 CC due to some unshrouding.


In 1966 and 1967 the 327/300 head went to 3890462 - again machined for 1.94/1.5 for 327/300. I do not think any of these were hogged out to 2.02/1.6. Combustion chamber was 64CC. The combustion chamber shape and plug location was slightly different than the 461's. I have pictures if you want.

Later 1967s 327/300 used 3917291. These are virtually identical to the 3890462 except there is a boss for a temp sender and the area around the pushrods is a little different. Some Corvettes even came witha 291 and a 462 as the production shifted. As a matter of fact I am using a 462 and a 291 on my motor.

As always - I HIGHLY recommend CCing the combustion chambers. I purchased a set of 461s that had been milled significantly and the size was 57CC which would have put my compression ratio at ~11.5:1 with the stock domed pistons. The other pair I picked up were 67cc (unshrouded) which put my comp ratio at ~10:1. I wanted 10.5:1.

BRian

 

[Fuelie]

Can anyone give me the info on the stock heads used on the 327/300hp engine from 63-67. I am looking for casting numbers and valve sizes along with chamber size. Thanks in advance.

Hi Moe Jr,

Here are the heads listed for those years:
'63 & '64 250hp = 3795896
'63 all others and '64 to '66 all engines = 3782461
'67 all engines = 3890462

My understanding is that the 300 hp engines came with 1.94" intake and 1.50" exhaust valves. As for the combustion chamber volume, I think they are 64 cc, but someone else may be able to confirm that.

Hope that this helps,

Brian

 

[MoeJr]

Thanks guys. I knew I could count on you.

:bar

 

[JohnZ]

'67 all engines = 3890462

Brian

If that's from the latest NCRS Spec Guide, it will be corrected for the next issue so it matches the Judging Guide; late 67's used the 3917291 from about April on. My June 1st 327/300 has the 291 heads, dated late May.

 

[Fuelie]

If that's from the latest NCRS Spec Guide, it will be corrected for the next issue so it matches the Judging Guide; late 67's used the 3917291 from about April on. My June 1st 327/300 has the 291 heads, dated late May.

Hi John,

It is from the NCRS Spec Guide. Thanks for the info update

Brian