DABE

What are some good heads for the carbed 305...i have a performer RPM intake...750 double pumper....agressive cam...and maybe a stroker kit (335ci)...what are some good streetable heads that yield the most HP gains?....im looking at the Word S/R torqer or the vortec L31 heads....thanks

Tom84L69

you've got the right idea. those are both good but i'm running my factory heads ported and gasket matched. they work great. my 305 is making about 300 horses.

I've also heard corvette L98 aluminum heads work well.

DABE

well....according to desktop dyno....im getting about 310 hp and 342 tq at the fly wheel with my setup...so...which heads would be better....im thinking the L31s are better...then i have to get the Performer RPM Vortec intake...and see where those HP and TQ numbers take me....

will my roller tips still work on the L31s??

Are they FAIRLY easy to install?

Should i try the stroker kit??.....ill do it over the summer when i have more time to have it installed...

Dave

five7kid

iTrader: (14)

You should shave the Vortecs or the Al L98's to keep compression up where it belongs. You should also have screw-in rocker studs installed and use much better valve springs if you go with the Vortecs. Your roller tips should work fine assuming they're self-aligning (but don't use them on the Al L98's unless you open up the pushrod holes).

Assuming a 10% increase for porting over World's published unported flow data, Desktop had my combo at 362 HP @ 6000.

Rather than stroke a 305, just get a 350. More cubes, more power, less money.

DABE

Are you suggesting getting the World 305 heads....i see that you are using them...are they worth it??...

jegs has them for 310 a head....is that a good price??...i want to get decent heads that i can use bolt on....i have heard Horror stories about shaving heads....and its too much money to risk....do you recommend getting the world heads??....they seem nice...1.94/1.50....

I can get bare World heads for 250 a head from martel brothers..then i can put the springs rockers that i have on the car now on them...then just buy some valves...

How much Hp and Tq will my car have with the world heads?....

305
Hooker headers 1 1/2
World 305 heads
Roller tiped rockers
XE262 comp cam
Edelbrock performer rpm intake
Holley 750 double pumper carb
Accell hei distributor vac. advance with accell hei hi output coil
TH-350 with 3500 stall
3.73 posi

Thanks
DABE

wasp

why would you need to open up the push rod holes?

Mark305TBI

yeah? Why would you need to open up the pushrod holes? I've got 'em on mine and I didn't do anything with the pushrod holes.

five7kid

iTrader: (14)

Perhaps I should have said guide plates (that's what the aluminum's use, correct? I've only had second-hand exposure to them). You only want one alignment system on the head - either SA rockers or narrow pushrod holes/guide plates. If you have SA rockers with one of the others, you'll get binding - not good.

The World heads are pretty good. They do benefit from bowl work, even by WP's own admission. If you don't do it, the improvements will be reduced. The prices you quote sound pretty decent. I spent $650 for the pair from Competion Products last year, including unassembled heads, completion kit (valves, springs, studs, seals, etc.) with upgrade springs and shipping. I've heard they've raised their prices, haven't checked personally.

iroc22

Why would you need to shave the AL L98's??? They're 58cc already.

Mark305TBI

I have heard of the L98 heads having guideplates but, mine didn't.

five7kid

iTrader: (14)

They are 58cc for a 350. That's to maintain the power that 64cc heads make on a 350. Aluminum doesn't retain heat as well as iron, which means you can run higher static compression, but also means you need to run higher static compression to make the same power.

It's simple physics. Heat and horsepower are energy. If you lose heat from the combustion chamber, it isn't being converted to horsepower. Higher static compression produces more power, so the heat loss is offset.

That's why you want to shave L98 aluminum heads for use on a 305. It would probably make more power with unshaved aluminum heads than the orginal heads produced, but it will be less than comparable iron heads (like the Worlds) and less than you could make with the aluminum heads shaved.

iroc22

Oh yeah I didnt consider that.

wasp

im confused............if you need 58cc chambers to keep compression up on a 305.........then you shave em to make up for the heat loss in aluminum.....what is your ending chamber size? and why couldnt you just polish the chambers to achieve this instead of shaving the whole head? man this head talk is confusing , there is another thing to consider around every corner!!! teach me wise men

DABE

i dunno what to do

Here are my choices

1. Vortec L31s (get RPM vortec intake)

2.L98 vette heads

3.World S/R Torquer 305s

4. Bowties<----mechanic recomended them to me

Im gonna make a poll....see what people think

Tom84L69

WASP when you shave heads, you increase compression by reducing chamber volume. so milling a 58 cc head will make it smaller, ie 57 cc. the more you mill it, the smaller the cc gets. that's the only way to increase compression without changing rods or pistons (except thinner head gaskets and block decking).

Just "polishing" the chamber or any grinding of the chamber will
reduce compression ratio by giving you a larger cc. think of the chamber volume as how much water would fit in the chamber (grind more out, more water fits).

Dabe, I'd do the L98 heads, they're light, respond well to porting, and can be found fairly cheap.

five7kid

iTrader: (14)

52-54cc would probably do it.

Polishing will help to reflect heat, but that isn't the whole story. The heat transfer property of the metal is also a factor. Ceramic coating is another possibility that both reflects and has low heat transfer characteristics.

DABE, go ahead and do a poll, but you'll probably get similar responses to what you got here. The choice I made is obvious, and I considered all of the heads you listed, except the Bowties, and one you didn't - porting stock 305 heads.

five7kid

iTrader: (14)

Tom, you beat me to the "Submit" button...

The point Wasp was trying to make is that polishing will help retain heat, and that's true. Simple polishing won't remove enough material to make a substantial difference in volume, but will improve power and reduce octane need due to the removal of hot spots that promote preignition.

Gotta run. More later if this topic continues...

DABE

alright....L98s it is....where can i get them for a good price??...

http://www.sdpc2000.com/cart.asp?act...id=277&pid=147

Get them bare??...i can put my newer valvetrain (springs and tiped rockers on them) then buy some valve...would this be cheaper?

DABE

DABE

another quick thing....will my Performer RPM intake still work with it??...i have a carb...does it matter?

DABE

Mark305TBI

Is your performer intake for the pre-86 style carbureted heads? Or is it the post-87 style? The L98 heads have the old style intake bolt angles. You can enlongate the bolt holes on the intake if it doesn't match up.

DABE

ok..i know i want the L98s...but how much should i spend??..whats reasonable?...ill get them new...i dont like to buy used car parts....Thanks for all of your guys help....ill have a wicked 305....then when i get cash for the 350...it will have a screaming setup...take my cam, heads, intake, carb and throw it on a 350 shortblock and ditch the 305 shortblock.

Dabe<---is happy

wasp

these guys are 50 bucks cheaper than summit.........if i cant find a reliable set used then im gonna get em here........on the intake question..............i have an edelbrock tbi intake on a 91 bird........are the bolt angles the same on a tbi as a carb intake? or will i have problems as well?


http://www.sdpc2000.com/cart.asp?act...id=277&pid=147

wasp

update......gmpartsdirect.com has em for 455 a piece 15 cheaper than my last post




12556463 Corvette Aluminum Cylinder Head Assembly
This aluminum cylinder head assembly for small-block Chevrolet V8s is ideal for street rods, fresh-water power boats, and high-performance applications. GM Performance Parts' aluminum cylinder head assembly combines the benefits of light weight, advanced design, and an affordable price. This complete head assembly includes valves, chrome silicon heavy-duty valve springs, retainers, 3/8" screw-in rocker studs-everything an enthusiast wants in a high-performance cylinder head package! GM Performance Parts aluminum cylinder head assemblies are based on brand new Corvette light alloy castings (P/N 10088113). The Corvette cylinder head's advanced design features include D-shaped exhaust ports that enhance the flow of burned gases, high-velocity intake runners that provide crisp throttle response, and centrally located spark plugs that improve combustion efficiency. Valve seat inserts for 1.94" diameter intake valves and 1.50" exhausts are installed in the 58cc combustion chambers. Raised rocker cover rails with machined sealing surfaces virtually eliminate rocker cover gasket oil leaks. This high-performance cylinder head assembly is used exclusively on High Output 5.7-liter small-block V8 engines. Unlike production Corvette cylinder heads, it is outfitted with special heavy-duty valve springs (see part number 12551483 for technical specifications). A pair of aluminum cylinder heads offers a weight savings of approximately 50 pounds over comparable cast iron cylinder heads. (A bare aluminum casting, less valves and springs, weighs 19 pounds, versus 44 pounds for a bare cast iron head). This reduction in total engine weight of 25 pounds each can improve handling, acceleration, and fuel economy.

Part Number...Description
12555269.........Stamped steel rocker cover
10229162.........Corvette screw-in oil filter cap
12342056.........Chrome screw-in oil cap w/GM logo
12338092.........Valve cover hold-down bolts (8 required)
14094717.........Hold-down bolt washers (8 required)
14088793.........Hold-down bolt gaskets (8 required)
14088564.........Neoprene rocker cover gasket
12557236.........Composition head gasket, .051" thick
12495499.........Head Bolt Kit
12495490.........Rocker Arm Kit
Technical Notes: Technical Notes: This casting does not have intake manifold heat riser or EGR passages. The exhaust port exits are approximately .100" higher than production cast iron heads; exhaust manifolds and aftermarket headers may require modification to maximize airflow. The spark plug holes are angled; check for adequate exhaust manifold or header clearance. Use 3/4" reach gasketed spark plugs with 5/8" hex heads (AC FR5LS), 904, or MR 43LTS. In rapid fire use #8 plug. Both ends of the head are machined for alternator, power steering, and air conditioning compressor mounts. No pushrod guideplates; use rail type rocker arms P/N 10089648. This aluminum head assembly requires valve covers with central hold-down bolts and extra-long bolts with washers. A composition head gasket with stainless steel fire rings is recommended to prevent galvanic action between the head and a cast iron engine block. This head assembly is the same as P/N 10185087, except valve spring and retainer change.

--------------------------------------------------------------------------------

DABE

nice.....thanks for the update

Dabe

five7kid

iTrader: (14)

You might check into Competition Products as well (www.competitionproducts.com). Their website needs updating, but it should have their phone number so you can call and get current prices. I got my heads from them; at the time the bare aluminum L98 heads were $50 more than the bare World heads. About $500/pr bare (that was last year).