What were these heads used on? and how would I identify the heads w/o removing the valve cover? Isnt the little pionty thing cast into the front of the head around the accesory bolt holes an indication of most older gm cast iron heads?

I have some may sell them.....if they are worth anything. I thought they came off of the 275/300hp chevy motors....

More likely Powerpack, early heads

More likely Powerpack, early heads

thats the other name my dad had for them....hes kinda smart. lol:yes:

Small heads, chamber and valves. They will fit the 55 you have.

Small heads, chamber and valves. They will fit the 55 you have.

yeah the 55 its the powerpack 283/265?. But a guy in my hometown said those heads where used by racers in the 60's. Said they were factory 283/327 vette heads. I has ACRES of old cars and parts...OLD CARS AND PARTS...my little 55, 68, haven. Truth is he wont let ANYONE except my dad even on his property. lol

NEWAYS the other motor I have has these heads. Would these heads be OK with the new 'THUMPR' camshaft from COMP cams?

ok guys HELP me out here... these are the numbers off of my fire pack heads...

3795896
gm12
a204

are run o da mill heads or what?
:confused:

Chevy V8 casting numbers

62-64 327 vette 250 hp
62-5 327 passenger
62-7 truck
63-67 283 truck/pass


http://www.mortec.com/castnum.htm yields the following

60cc head - small chamber as posted above.

I had a set of the "power pac heads" which had a traingle on the head with the 1.71 valve. They made no more than 5400 RPM on a 350 as there is not enough airflow to make much HP. Dont know if what you have is referred to that or not....


Lane

I also just noticed that these heads have NO accesory mounting holes...what does this mean?
Are these heads worth selling?

Would they be OK with a 280h comp cam in a 8.5:1 motor?

I also just noticed that these heads have NO accesory mounting holes...what does this mean?
Are these heads worth selling?

Would they be OK with a 280h comp cam in a 8.5:1 motor?

No bolt holes means not accessories bolted to head like alt mount, AC braket. Most those brackets were hung on outside mounting holes like water pump and exhaust manifold mounts. Think you could do better .

Accessory bolt holes did not appear on cylinder heads until 1968.

The PowerPak heads you have were good for the camshaft technology/design of the 50's & 60's. Rarely, was their a cam with more than 220*@.050" lift, .440" of lift, and less than 110* LSA. I remember cams were catalogued as 3/4 race & full race.

The engine combo's then were awesome, still are. Listen to one driving down the street, a 283 w/PowerPak and a Carter WCFB wide open.

However, as said, rpm limiting, 5500 max, maybe 6K.

That little 283 Chevy with power pak heads surprised a lot of people back in the day. A popular cam in 50s-early 60s was called the "Duntov Cam" which was designed by Zora and was a Chevy part available at the service counter. It was similar to a 3/4 race cam sold by aftermarket cam co.
With 2 4BB set-up, Duntov cam, power pak heads, low restriction exhaust system, in a relatively light wt. 55-57 Chevy (for its day), the little 283 mouse would run with the big boys.

So these heads would be ok with how big of a cam? help me out here gearheads....

268 High Energy cam.

268 High Energy cam.

Thanks again Everett, I was thinking the High Energy 274H from comp...Ill probably go that route...That new 'Thumpr' cam sure sounds good tho...:yes:

you will be sacrificing so much power and torque using these heads compared to newer head designs that it not even funny. This head design is 45 years old and the best place for them in on a numbers matching car that should have had them installed at the factory

you will be sacrificing so much power and torque using these heads compared to newer head designs that it not even funny. This head design is 45 years old and the best place for them in on a numbers matching car that should have had them installed at the factory

Kind of depends on what he is building. I didn't see that posted anywhere.:beers:

Kind of depends on what he is building. I didn't see that posted anywhere.:beers:

Gary I am sticking a 10 to 1 350 together that will be a torq monster. I know that small heads will give me gobs of torq as long as I chose the proper cam. Most motors I have built in the past were all operational from 5500 to @8k. I havent done small chevy motors that were designed purely for torq to play on the street.
When I do motors I usually shoot from the hip, and do really well. Since I have recently aquired a pretty sweet 68 RS/SS I thought I would get opinions from some guys with a little more experience than I.
BTW the coolest motor I ever done was for my 71 rs car. only cost my 6k. 8.5:1 pump gas 383 stroker with a turbo off of a ford 7.3 liter diesel engine. :yes: Took a LONG time to get it right but it was a beast.
Thanks guys keep suggestions coming!