Djaustin89

iTrader: (5)

Can this be done? and what compression ratio would we be looking at, also what gains if any.

AKlowriderZ71

iTrader: (22)

No, it cannot be done.

white lightning SS

iTrader: (3)

None of the new LSX heads will fit that engine. There are many aftermarket companies that make performance heads for that older Vortec motor.

James B.

iTrader: (1)

The best heads you can put on to a naturally-aspirated L31 Vortec 350 are Edelbrock E-Tec 170s. They are smog legal.
The stock iron heads flow very well. Their problem is not flow it's the limited lift they handle and the pressed-in rocker studs.
A head-swap on a Vortec 350 would see little benefit in power up to 4500RPM, from there on the valvetrain supports higher RPM than the stock heads and there would be no floating like the stock heads, so more power.

With the 170 E-Tecs it becomes possible to run a bigger cam, guide plates, and non-self-aligning full roller rockers. The stock covers fit them too. Shift points can be bumped up to 5500RPM.

Part Numbers:
Heads: Edelbrock 60979 (each)
Plugs: NGK BKR6E-11 (gap to 0.050")
Gaskets: Cometic C5474-040 (each)
Bolts: ARP 134-3701 (12pt Black Oxide)
Rockers: Comp Cams 1017-16 (Full Roller, 1.5:1, non-self-aligning, narrow body)
Timing Set: GM 12371043 (Single Roller with thrustplate)
Cam: ? (make sure stepped-nose for factory roller-cam block)
Pushrods: ? (check geometry and order to length, hardened)

Aluminum heads will support tuning in additional timing advance without pinging.