i would guess the sr's are better but i really dont know, any ideas?

 

Either way isn't a bad choice in my opinion. The World products heads have more potential if they are ported. But out of the box I think they are about the same as a set of well ported stock heads. I had my stock heads pocket ported, bowls blended, 3 angle valve job and milled .03 for more compression. I was able to get my 305 with a stock bottom end down to a 13.4 1/4 mile at 101mph with the mods in my signature. I would probably go with the world products heads or vortec heads just because they have more potential than stock heads.

 

LG4 heads make more sense if your on a tight budget. Me I'm cheap, so I'm looking for a set to port and toss into my car.

 

Another 10 hp can be gained by enlarging the intake valve to 1.94 over the stock 1.84.

Porting and polishing the 305 heads is a greart idea

 

I ported, gasket matched, and polished my World heads, used an LG4 head for practice.

Go with the Worlds. They're better castings, have a re-designed chamber (although still 58cc), better port shape,and clean up easier. In order to make the LG4 heads "equal" (which isn't really possible), you'd have to do the aforementioned 1.94" intake valve, which means machine shop work (unless you have the equipment available) to rough the larger seat before you start die grinding, and 8 new valves. Also, the Worlds have screw-in rocker studs, which means more machine work and new parts to put them on the LG4 heads. By the time you get them to "World class", you'll spend as much or more money than you would have just getting the Worlds, and still end up with an inferior product.

Vortecs on a 305? Please. Not only will you have the same factory-quality casting issues, you'll have press-in studs and too-large chambers to deal with, and will need a more expensive manifold to bolt to them. Again, more money to fix than simply getting the Worlds.

But, if you can live with the stock size valves and press-in studs, porting factory LG4 heads is a good budget thing to do.

 

I have a set of 416's you can have for the cost of shipping (not the one I practiced on). They'll need a valve job when you're done, guides would benefit from knurling or replacing. New springs also a good idea. Valves were sealing, but as mentioned above, if you go with 1.94" intakes, you'll have to spend money to get the seats enlarged and new valves.

 

Now guys, THAT'S how you bring high performance heads in on a budget--get the heads for free and work them up from there!