1982 350 new heads questions

[TwoFiftyShifter]

Hey guys, easy one here. I just sold an M20 transmission for 600 bucks so I can afford new heads. My 82 K10 has a good wrench 350 with a Qjet and headers. Has about 50K miles on it. Puffs a bit of smoke on startup, but doesn't use much oil. I drive highway and have 2.73 gears. Would like a bit more low rpm torque.

If I get vortec heads, I will need to get a spread bore vortec intake. So,

Should I get a set of heads that use the old style intake? Is there something comparable to the vortecs for daily driver usage?

Would going from 76cc heads to 64cc add enough compression that 87 octane might be too low?

Should I go Summit/Jegs brand vortecs at $350 each, or the chevy performance that I see for 450 each?

What exactly are "self aligning rocker arms"? Are they easy to put on? I have not done a head job before.

[AussieinNC]

Self aligning rocker arms...
Essentially it means that the tip is designed in such a way that it cradles the valve stem and keeps it from turning off sideways.
You must provide directional support for the rockers somehow, if you don't run self aligning rockers you will have to install hardened push rods and guide plates in order to use them. Non Vortec heads use machined ports in the head surface to align the push rods.

The factory Vortec heads use light, single-wire valve springs with a damper that generates between 70 and 80 pounds of load on the seat.
Because these heads are meant to work with a 1.5:1 rocker, their tall valve guides can only handle maximum valve lifts of around 0.420 inch. Anymore lift and you will need to perform some engineering work to make it work.

Lets say you have a compression ratio of 9.0:1 with a 7 6cc head and .021 gasket.

Then you change the head to 64cc and the gasket to .039 and you get 9.79:1

9.79:1 would require a higher grade octane fuel to prevent engine damage.

If you are just concerned about the puff of smoke at start up, replace the stem seals and check the valve stem wear...

Just my two cents worth...

[garyd1961]

Originally Posted by AussieinNC

Self aligning rocker arms...
Essentially it means that the tip is designed in such a way that it cradles the valve stem and keeps it from turning off sideways.
You must provide directional support for the rockers somehow, if you don't run self aligning rockers you will have to install hardened push rods and guide plates in order to use them. Non Vortec heads use machined ports in the head surface to align the push rods.

The factory Vortec heads use light, single-wire valve springs with a damper that generates between 70 and 80 pounds of load on the seat.
Because these heads are meant to work with a 1.5:1 rocker, their tall valve guides can only handle maximum valve lifts of around 0.420 inch. Anymore lift and you will need to perform some engineering work to make it work.

Lets say you have a compression ratio of 9.0:1 with a 7 6cc head and .021 gasket.

Then you change the head to 64cc and the gasket to .039 and you get 9.79:1

9.79:1 would require a higher grade octane fuel to prevent engine damage.

If you are just concerned about the puff of smoke at start up, replace the stem seals and check the valve stem wear...

Just my two cents worth...

I agree with most of this but I think you got your max lift for vortec heads wrong. There is some controversy about how much unaltered vortecs can handle but the 350 vortec comes from the factory with .429 exhaust lift.

[Tom]

Factory vortecs on the 350hp crate motor have almost .480" lift with the 1.6 rockers they run. If chevy will warranty it then it must work ok.

Putting vortecs on a basic 8.5:1 350 is a great idea. You'll get about factory vortec 350 compression. You could get used oem rockers if you want to go really cheap. I prefer the oem vortecs to aftermarket versions but that's just me.

[Redchevy87]

I’ve been thinking about doing the same thing. Would slapping on some vortecs with a good intake and 4 barrel make a noticeable difference without a cam upgrade?

[Tom]

Originally Posted by Redchevy87

I’ve been thinking about doing the same thing. Would slapping on some vortecs with a good intake and 4 barrel make a noticeable difference without a cam upgrade?

Yes.