sheldon87cam

hi i`m doing a complete ground up resto of my car i`m putting back the 305 lg4 but ptting some extra things on i had block bored 30 over sealed power flat top pistons crank done and in stalled edlebrock cam 3701 for the lg4 i also have edlebrock intake and headers for this engine & a new 600 cfm holley carb my question is i`m thinking about new heads instead of having factory 416 heads rebuilt what heads would be best to use with this combo or just go with factory heads , i also have a new factory dual snorkel air cleaner setup to put on car the car has a 5 speed with factory 373 gears thanks sheldon

305sbc

iTrader: (3)

When you say "best" we don't really know exactly what you're looking for.

For a resto, just reconditioning the 416 heads is all you need. They probably need valve-guide inserts and a new valve-job, general cleaning, resurfacing, and new seals.
You can have the springs tested to see if they are tired. If they are okay, then you might want to shim them a little to bring up the seat pressure for your new cam. Be sure to used the hard stainless shims because your stock springs have damper coils in them.

If you keep valve-lift under 0.468" then you don't have to machine the guide tops or swap retainers. You also shouldn't need screw-in studs or guideplates.
Pocket porting the 416 heads will easily add 30 hp to a 305, and a 3-angle valve-job can add 10 to 15 more.

If you're going to use a fel-pro head gasket with a compressed thickness of 0.038", then you'll want to have your block decked for a piston-to-deck height of -0.010". Otherwise you'll want to run a thin gasket like the factory one that's around 0.010".

sofakingdom

iTrader: (1)

Edelbrock 3701 is an intake.

What cam are you REALLY putting in it?

Hopefully not REALLY an Edelbrock one? Because any of them are pretty much a mistake... the "Performer RPM" cam because IT SUCKS and is a total mismatch for a 305; the regular "Performer" because it's overpriced, as you can get the EXACT SAME cam for half the price here.

Damon

There are very few "performance" heads built specifically for the 305. Typical 350 performance heads with 2.02 intake valves are a poor choice- the valve is severely shrouded in the small bore and will actually CONTACT the bore at relatively modest lifts (about .430") in many cases.

Trick Flow makes a 305-specific aluminum performance head and it's very nice, but you can imagine they don't give them away for peanuts.

Others have used factory 350 Vortec heads (which only have a 1.94" intake valve that fits down the 305's bore) milled down a little to maintain compression. They're relatively cheap and work gread but require a Vortec-specific intake and self-aligning rocker arms that add to the overall cost.

Your cheapest route is the heads you already have with a good valve job and maybe some pocket porting. Just don't go crazy throwing money into them- nobody will pay a nickel more for that work if you go to sell them later.

sheldon87cam

2101 intake & 3702 cam sorry

sofakingdom

iTrader: (1)

That's basically a stock cam... it'll work, just don't expect much. And of course it shares the price problem with the others of their cams.

But, stock heads, the mostly stock cam, and mostly stock intake, should work OK. Nothing is "out of place" so to speak. You'll end up with something not dramatically different from what you started out with, except newer parts.

sofakingdom

iTrader: (1)

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rusty vango

you really cant beat the "416" head for a 305.properly ported they are a good choice.i have a set on my 86 TPI car and im getting around 22 mpg on the freeway

Damon

FYI- the Summit house brand K1102 cam kit is the same thing as the Performer cam. And the price is right- $85 including lifters. I've used several Summit cams over the years. While not the "cutting edge" of lobe design, they are a quality part that will last a long time in a daily driver, won't beat up the valvetrain parts and won't be noisy.

And mild though it may be, that cam has 20 DEGREES MORE DURATION than the factory LG4 cam. With a better intake and exhaust it will feel like tyou strapped a second engine under the hood.

I have it's bigger brother, the K1103, in my super-mild 383 blower motor. It makes the same power as a custom grind Comp XE cam I had in the motor previously but the valvetrain is a lot quieter which was really annoying me with the XE cam.

You have a solid game plan. Keep going.

blue birdy 87

[QUOTE=Damon;5143881)

Your cheapest route is the heads you already have with a good valve job and maybe some pocket porting. Just don't go crazy throwing money into them- nobody will pay a nickel more for that work if you go to sell them later.[/QUOTE]


What is pocket porting?

sofakingdom

iTrader: (1)

"Pocket porting" is the name some people use for working on the bowls right behind the valve. Which is the part of porting that does about 90% of the good... "gasket matching" and "polishing" are largely a waste of time, the gains are achieved by smoothing out and properly directing the airflow along THE ROOF of the port as is makes its 90° turn to hit the valve, and flows mostly in the space between the valve guide, the roof, and the "common wall" (opposite the intake push rod). Which incidentally is why smoothing out the push rod pinch, another common beginner waste of time, is .... a waste of time .... because very little of the flow is occurring over there. That portion of the roof I just described including making the guide into a "teardrop" or "airfoil" type of shape, and getting rid of all the weird angles where the casting meets the cutters and all that right immediately behind the valve seat, is where power is made, in stock heads.



Here's a set of heads (not stock) where you can see the parts of the port that are responsible for the flow, and kind of what it should look like when it's done.

Damon

...... and the blue boxes are showing steam holes used ONLY with a 400 block. They have nothing to do with a 305 block like yours. Just thought I'd mention that before you wonder why Sofa would be highlighting some deck holes instead of the ports. Ignore the boxes and look at the ports right behind the valve seats. THAT'S what a properly massaged port looks like.

80% of the improvement from porting happens within 1/2 an inch of the valve seat. That's what "pocket porting" is- just the work near the valve seat, not the entire length of the port. Just like Sofa explained.

sofakingdom

iTrader: (1)

Right... ignore the steam holes. Thanks DAmon. Not a part of the discussion at hand. Just look at the ports. I had orignally put that set of pics on here to show those, but they're great pics for lots of other teaching points too.