wasp

afr did but doesnt anymore as of the first of the year, slp didnt know anyone who does................dont tell me im s*** out of luck here if anyone knows id appreciate it

Mark305TBI

Aluminum L98 heads will work with a 305. I don't know if you were dead set on aftermarket, though.

wasp

i want real good flow rate......i know afr is top notch on flow rate thats why i was going with them , also the fact that b4 i found this board they were all i could find that made them..........now its back to sqaure one......should have bought them in the fall i guess.........L98 are stock aluminum heads correct? probly not ported then and sub par flow rate ?

Mark305TBI

SDPC ported mine. They flow a decent amount (nothing real special though). Lingenfelter offers ported Al L98 heads that do flow an especially decent amount. Be forewarned, however, they'll cost you more than twice what my SDPC heads cost me.

Mark305TBI

I've got the flow numbers for the stock and for the SDPC ported heads on my website.

wasp

just spoke to lingenfelter they dont make 305 heads , and yes i know , one of his heads is equal in price to a set of someone elses........crazy........anyway lingenfelter said to try gm performance parts but when i try to find them online all i get is a bunch of dealers with gm performance parts under their name......where is the real deal? also who is sdpc?

Mark305TBI

Scoggin-Dickey, a GMPP dealer. The L98 heads aren't actually "305 heads" they're 350 heads that'll work on a 305.

wasp

yes afr was doing the same deal , 350 heads with smaller valves, just need to use a 350 head gasket.........soooooooooooo........in order to price a gm performance aluminum head i have to go thru a dealer? if i can get the heads ill ship em to get em ported........however that mat cost a fortune since they are so heavy........help!!!!:sillylol:

E-Z Rollin

The L 98 alum heads have 58cc chambers, which is what you want with a 305 to keep the compression up. Also, they have 1.94 intakes,any bigger and the valves will hit the cyl. wall. You can get these heads cheap on the used market,just make sure they are complete and in good shape.If you pocket port these heads they flow all you need for a streetable 305 , anything more is just overkill. Keep in mind that a given sized engine with cam,comp. etc. only needs a certain amount of airflow. It's possible to have "to much head" for an engine.

wasp

oh yeah? its possible to have too much flow? ok 58cc is what ya want on a 305 , can i get the valve sizes so i can make sure i get the right head? also where can i get new L98 aluminum heads? ill buy those heads and have em ported maybe mail em to afr or someplace like that.....i dont really have a local guy id trust to port my heads............lemme know

wasp

ok just talked to summit, they say they can get me L98 aluminum heads brand new for 528 a piece............im assuming they have 58 cc chambers like you said altho i didnt ask...i did ask the valve sizes however......1.94 intake and 1.50 exhaust......would those sizes work on a 305 with a felpro 1010 350 head gasket?.....................also are those center bolt or normal valve covers? and ball park what ya think i should pay to have em ported? and who would ya recommend? 1000 for a set of heads is cheap if ya ask me

wasp

just a follow up.....i know i know i ask a hell of alot of questions but mama always said dont be afraid to ask hehehehe.............that head came on a 350 vette motor originally correct? why then would the valves be small enuff to work on a 305?

wasp

and yet more questions:sillylol: my motor is a 305 tbi in a 91 bird.....im not sure but i think there is a special passage in the stock heads for the egr? i remember because when i did the intake manifold edelbrock told me i had to use the original gm gaskets , i couldnt use aftermarket intake manifold gaskets........would that be an issue on these heads? also i have crane roller rockers on my stock heads now.....would they match up onto the new heads without a problem? and lastly , is the head heights the same? meaning would my stock head bolts work and would stock pushrod length remain the same? thanx in advance

Mark305TBI

There is no EGR passage in the heads. The '87-'91 Vettes used a special external EGR system.

I've got Crane Gold Race 1.6 ratio roller rockers on my L98 headed 305.

I've still got the stock pushrods too.

Sitting Bull

Why does it have to be aluminum?

Why not use the World S/R 305 heads? They are iron but will give you excellent performance.

Or just take those stock 305 heads, get the Standard Abrasives head kit and do the porting yourself? It even includes a video showing you what to do, You'll get plenty of performance out of them, especially if you reem the intake valve out to 1.94.

Car Craft and Chevy High Performance have both brought out excellent articles this year showing you how to do the porting yourself.

In any even, both of these choices are a LOT cheaper than buying new L98 heads

Mark305TBI

$528 a head is a rip for Al L98 heads. I got mine brand new and ported for about that.

Damon

If you're interested in a set of aluminum L-98 heads I have a fully assembled set BRAND NEW IN BOX, never used, never touched, never bolted on an engine, never anything. I'll let 'em go for $650. Valves, springs, rocker studs, guideplate, etc. Just like they come from GM, cause that's where they came from.

You are correct, they have no exhaust crossover passage and can not be modified to add one. Not many people are concerned about defeating the EGR valve. It'll still be on the intake and LOOK fuctional, but there will be nothing flowing through it, that's all.

Shoot me an email if you're interested.

wasp

and where was that?

wasp

so why not just remove the egr and put a plate or something on the manifold in its place? that wont be detrimental to performance or f up the comps function?

wasp

cuz i want it right...im not gonna learn how to port heads on my own heads...maybe i can practice on yours? lol.....and i want aluminum because anyone knows speed is power to weight ratio........

Mark305TBI

www.sdpc2000.com

wasp

mmmmmmmm 470 at sdpc lets see 940 plus 40 shipping......980............530 at summit 1060 plus 7 for handling........1070 ya save me a hundred bucks mark ......any one else can save me a few bucks? hehehehehe thanx dude........also i talked to slp.....they seem to think if i eliminate the egr without having a custom chip burned the 305 will run rich as hell.............it runs rich now........any thoughts? cuz i really wana wait till i put no2 on b4 i get a chip burned

Mark305TBI

Damn. The prices have gone up on those heads . Good thing I've already got my set .

SoCo80p

iTrader: (5)

have you conciterd going 350? you'll get ALOT more power and can use it better, the 305 isnt a deep breather and bit *** flowing heads wont benifit it alot, you can get a 350 dirt cheap and the money will go ALOT further with it

wasp

yeah but i wana kill the 305 first......then im either gonna put in a supercharged 350 or 383............till i get my z6 vette of course or z5 i forget now lol

Sitting Bull

Go ahead and buy them if you want. I have a set of bare castings so come and work on 'em!

That measly little 30 pound difference ain't gonna get you anywhere fast, but to each their own