Who Knows His Humps- SBC 327 Heads???

Over the years I've had six or more 327 engines and probably a couple dozen double-humper heads (castings 461, 462, 186, etc.) Today I got to looking at the 327 engine in the '68 Chevy that I bought from a little old lady who is too old to drive anymore, and after scraping the grease away at the front of the un-drilled head, I found what looked like a power-pak head but instead of having a tent peak centered on top of the reclining rectangle, it has a round hump instead on top of the rectangle --- the hump is about the same size as the humps on a double-humper, but there's only one. I have never seen that particluar head before. Anyone know their vintage SBC heads well enough that they can tell me about this head? By the way, the '68 Chevy is an unmolested car that the old-lady's deceased husband bought new in '68. It still has a nice running 327 and powerglide, but is a 4-door, so the drivetrain is probably going into a Model A coupe project.

 

Bactrian 194's

tim

 

Say, What??? I don't follow. "Bactrian 194", meaning 1.94 inch valve? What about combustion chamber size, etc?

 

Any head I've ever seen with the symbol you describe was a small valve style (1.72 intake, 1.50 exhaust) head.

 

That's certainly something I've never come across in my travels! My guess, for whatever it's worth, is they're probably 194's. seems like a "standard" smaller valve head. I'm curious to learn more about this set of heads!

 

Sounds like the '68 version of a 250hp 327---small valve heads and a quadrajet.

 

Take a pic of it. I thought I'd seen everything on older chevy heads but this is a new one on me. Pull the valve cover if you get a chance and get the casting #

 

Likely one of these two versions:

[FONT=Verdana, Arial, Helvetica, sans-serif][SIZE=-1]"292" – 3917292, or 340292. Both are good performance heads. The 3917292 was found on 1968 327 and 350 engines, had 1.94/1.50" valves, 64CC combustion chambers, straight plug configuration, not sure on the accessory holes, and I do not have any port volume data on these heads. [/SIZE][/FONT][FONT=Verdana, Arial, Helvetica, sans-serif][SIZE=-1]
"040" – 3947040. A good performance head (I have read). Supposedly these heads came on 1968 327 truck engines. They had 1.94/1.50" valves, 64CC combustion chambers, DO NOT have accessory holes. I do not have any port volume data for these castings. These heads also had a single triangular shaped casting mark (slope on the upper left).[/SIZE][/FONT]

Might also be these, although it says these DO have the accessory holes:

[FONT=Verdana, Arial, Helvetica, sans-serif][SIZE=-1]"041" – 3947041, also 3947041X. A good performance head. They were found on 1969-1970 302 and 350 engines. They had either 1.94/1.50" or 2.02/1.60" valves, 64CC combustion chambers, DO have accessory holes, I don't have port volume data for the regular 041, the 041X intake port should be 165CC's, the 041X exhaust port should be 65CC's. These heads have a single somewhat triangular shaped casting mark (slope on the upper left).[/SIZE][/FONT]

 

Oh by the way, there were some double hump heads that had the bolt holes cast in the ends. The flat machined surface on these covered up part of the rectangle with the double hump to where only one hump shows. I've had one set of those, very desirable.

 

there's a set of '68 327 heads on ebay referred to as "single hump"

 

the 290 casting....standard casting on a lot of stuff in 68

 

Ok, Bactrian has to do with Camels. There are two distinct types Bactrian and Dromedary (I think). The reference is to the humps, get it humps -- Camels. Don't blame me it wasn't my post.

 

heres a good site:
http://www.chevellestuff.com/generic/head_casting_by_year.htm

 

If there's any daylight left when i get home this evening, I'll try to take a picture of the single-hump 327 head. 'Hope to be picking up a running 425 Nailhead engine and tranny right after work though, so it may not happen tonight.

I don't want to pull the valve cover (to see the head casting number) and possiblly cause a lot of work in sealing the gasket, so I'll save that until I need to do a rebuild. 'Just not worth the hassle to satisfy my curiosity. In the meantime, think I'll see what the single-humper heads on egay say.

 

If my memory serves me correctly when the 327 first made it,s appearance in 1962 as a 250 hp engine the markings were a single hump . In 63 a 300hp version was available with double humps but the 250 hp engine was still available until 1965.In 1966/67 the 327 became a 275 hp engine with double humps and then from there it all got too crazy.

 

Just another version of the Power Pack heads, with small ports and valves. Pull a valve cover and see if it says "CANADIAN" anywhere. Butch/56sedandelivery.

 

I Humped Last Night !! >>>>.

 

i had a 65 ish fuelie 327 that had heads like that one it, basically a single hump head if that makes sense, when i got the motor it was freshly rebuilt and had a vette fuelie intake on it.

JEFF

 

I can remember when I used to be able to double hump!!!

 

Come on man! The single humps are Dromedary, the double humps are Bactrian.

 

so the Equestrian has NO humps...amazing how that works

 

Found a set of Single Hump Heads in South Carolina. It is on a 327.

 

It means its a dromedary instead of a camel. I think I got that right one only has one hump.

I think in the case of these heads you are going to have to locate a casting number and go from there.

What kind of Chebby did you buy from the little old lady?

 

'67-'68 307 327 heads, 3917290 casting number.

 

Another back from the dead, but,---.I had a set off a 327 that came out of a 68 El Camino. They were small valve heads.

 

3917290 327 68-70 1.72/1.50
3297185 307/327/350 57-67 1.72/1.50

 

Not totally related but knew a kid n high school who was a master of fakery on chevy stuff. Used silly putty & molded camel hump shape off real set of heads n filled his silly putty mold with jb weld pasted double humps on a set of small valve no accessory hole heads. Looked real. . Later on he graduated up to using winters foundry gm intake "snowflakes" & various firing order & block casting numbers & pasting them on all kinds of stuff using vasaline as a release agent between silly putty & jb weld "machinist foil" for raised square number pads & a needle scaler to help blend the fake markings in, needless to say he got real good at it. Now he's into old corvettes ...... Go figure. Ohh & he said advertising an old vette as numbers match & saying original engine numbers match are two different things! Flux

 

The picture of the camel hump's is lacking the "461" casting from pre-67, not too much different from the "462"s. I have a pair of NOS "291"s on my Nova l79 engine..

 

a Domedary has one hump a Bactrian has two humps. so those will be dromedary heads. they will be low horse 172 intake heads. The Hp camel humps all have two humps some have the larger 202 intake valves

 

The 1962 & later 250 Hp 327 used the 283 Power Pack heads they have a pyramid on them. and the 300 horse 327 with double humps and a carter AFB carb & intake was available in 1962