Marine heads

[Bludacious]

If I were in your position and going through the trouble of a head swap, I'd go just a bit deeper and add a cam to the mix. That will likely net you more power gain than a head swap. Goodwrench replacement engines have pretty lame cams.

I'm planning on a moderate cam in the future, but as it sits now better heads is a relatively quicker swap for this car since it is my daily driver and I have a new carb in the mail anyways. Cam means taking out the radiator and water pump AND heat exchanger (AC car) which is a bit more involved.

 

[fleming442]

But, see, now is the time to do it. Get the heads milled to desired compression/CC, pick an appropriate cam, and do it in one shot.

 

[DRIVEN]

It is more work. But if you do the cam later you still have to pull the valve covers, rockers, pushrods, distributor, carb, intake, and drain the coolant and oil again. Saves a bunch of time and gaskets to just do it once.
Then again, if you just do the heads alone you can update us on whether or not you could actually tell a difference with just swapping stock 305 heads for stock 305 heads.

 

[Wraith]

I'd ask what rear gears do you have, more boost will be felt there per dollar than just a head swap sans cam and supporting items.

 

[DRIVEN]

^^ #1 performance upgrade for 95% of Gbodys.^^

 

[Yav8]

If your going to do all that work for only a little gain, then just do a 350 swap and gain the extra 45 inches making more of everything.

 

[84 El Camino 231]

I say be happy with what you've got but if you wanna spend then go BBC and/or fuel injection. Having heads detailed is usually expensive thus consider new aluminum edelbrock heads but check them carefully, they'll likely need some light work (check concentricity for good seat sealing).

Nothing special about marine heads, best improvement for chev heads is unshrouding the valves. Big valves shrouded are slightly better than having small valves.

If they're 350 heads, I believe the valve heads are too big and likely bounce off the cylinder walls of a 305, head gasket might not even seal properly.

I drive on highway myself, so I like tall rear ends but getting something shorter will definitely help the hole shot. How do those guys running 4:11's stand those high RPM's?

 

[DRIVEN]

I say be happy with what you've got but if you wanna spend then go BBC and/or fuel injection. Having heads detailed is usually expensive thus consider new aluminum edelbrock heads but check them carefully, they'll likely need some light work (check concentricity for good seat sealing).

Nothing special about marine heads, best improvement for chev heads is unshrouding the valves. Big valves shrouded are slightly better than having small valves.

If they're 350 heads, I believe the valve heads are too big and likely bounce off the cylinder walls of a 305, head gasket might not even seal properly.

I drive on highway myself, so I like tall rear ends but getting something shorter will definitely help the hole shot. How do those guys running 4:11's stand those high RPM's?

I don't think you'll find too many guys running 4:11s on street cars. It seems that 3.23, 3.42, 3.73s with overdrives are the norm. All way less lame than 2.29s or 2.56s that lots of Gs came with.
Deeper gears really do make our cars feel like they've got an extra hundred horsepower.

 

[84 El Camino 231]

I forgot to mention, the marine heads most likely will have stainless valves installed. As far as rear gear goes, 2.71 without OD is about all I can stand but to each his own.

 

[Clone TIE Pilot]

The only marine heads that would be worth it for 305s would be the 8059 Vortec heads for 305s. There are guys on Thirdgen making 300 hp with 305s with 059 heads.