Chevy - L98 Aluminum Heads. Any Good?

Mostly just a bench build, thought exercise.

Let's say I've got a 1972 Chevy 350 small block, that I'm considering swapping into something, and trying to get the total weight as low as possible.  Aluminum heads (and intake) are a sure way to drop lots of pounds.  I've found a pair of Corvette L98 heads for cheap ($350 ready to bolt on).  Are they going to be a performance upgrade too?  Or just weight loss?

Depends on the cam and current heads.

Supposedly pretty good (l98), d port exhaust. Intake pattern is slightly different if i remember correctly 

The L98 heads don't hold up to modern cylinder head designs, but they aren't a terrible cylinder head. Some port work and upgraded valves can make them perform solidly. Really, it depends on what motor they are going on. If it's a mild-compression, mild-cam 350 or 383 with a dual-plane that's just seeing street use, sure, go for them. If it's an 11:1, solid-roller 408 or 427 with a tunnel ram that you are racing, you might want to look elsewhere.

NickD said:

The L98 heads don't hold up to modern cylinder head designs, but they aren't a terrible cylinder head. 

This. I looked at these as well, but for $600 I got a much better flowing head new. 

Over 1972 heads, weight loss and compression bump, not sure there is a flow increase.  I don’t think $350 is cheap for L98 heads

bobzilla said:

NickD said:

The L98 heads don't hold up to modern cylinder head designs, but they aren't a terrible cylinder head. 

This. I looked at these as well, but for $600 I got a much better flowing head new. 

Yeah, the price on aluminum heads has gotten to the point where there is no reason not to run them really. I always liked the guys writing into Hot Rod Mag asking about getting a set of Pontiac iron heads refurbished and ported and Marlan Davis would always point out that by the time you put hardened valve seats in and all new valve seals and had them milled and ported, you were more spending more on iron heads that would flow less and force you to run less compression than you would just buying a set of new aluminum heads.

Used Aluminum heads should only be bought FROM a Machine shop.they need to go there anyway  Maybe unless you saw them run before you cooled it and removed them.

only reason to fix and use factory stuff today on older engines is for resto work.

for power newer castings cannot be beat

Dusterbd13-michael said:

Depends on the cam and current heads.

Supposedly pretty good (l98), d port exhaust. Intake pattern is slightly different if i remember correctly 

So, does this mean a "standard" SBC dual plane intake won't bolt up?

bobzilla said:

NickD said:

The L98 heads don't hold up to modern cylinder head designs, but they aren't a terrible cylinder head. 

This. I looked at these as well, but for $600 I got a much better flowing head new. 

Can you point me towards the heads you picked up?  ($600 each or for the pair?)

Patrick said:

Over 1972 heads, weight loss and compression bump, not sure there is a flow increase.  I don’t think $350 is cheap for L98 heads

$350 is price for a pair.  Can you get them cheaper?  I'm all ears.

In reply to GTXVette & NickD :

Mild "RV" cam already in it, and currently runs and drives.  Main goal for the swap would be weight reduction.  And I'm trying to see If I can get it done cheaply enough to get the car to the challenge.

Indy-Guy said:

bobzilla said:

NickD said:

The L98 heads don't hold up to modern cylinder head designs, but they aren't a terrible cylinder head. 

This. I looked at these as well, but for $600 I got a much better flowing head new. 

Can you point me towards the heads you picked up?  ($600 each or for the pair?)

 

Looks like they increased $100, https://www.ebay.com/itm/SBC-CHEVY-327-350-383-NKB-200cc-ALUMINUM-HEADS-64cc-STRAIGHT-PLUG-NKB-272/331929029050?hash=item4d488309ba:g:DuwAAOSwvgdW2LNy

The only thing I had to still pick up were screw in rocker studs. 

Indy-Guy said:

In reply to GTXVette & NickD :

Mild "RV" cam already in it, and currently runs and drives.  Main goal for the swap would be weight reduction.  And I'm trying to see If I can get it done cheaply enough to get the car to the challenge.

Yeah, in that case, the L98s will likely get the job done. Although a little port work probably wouldn't hurt. 

Well... here just my cent...  ( sad story :-) )

On Nov 2014 i bought a pair of L98 aluminum heads (5+ years ago... )

I bought it from summit, this one : https://www.summitracing.com/parts/NAL-12556463

Everything was ok... just .. the ups guy gave me just a single head... daamn.. !... 

so after clear my throat ... i discovered the small word ... "each" properly advertised at that moment in the summit page..

well... short story i have a paperweight that cost me almost $ 600 ... 

the second part of the story is my headers (hedman) fit in the angle spark plug style head... but since i never installed the zz4 heads.. i have some clearance problems in the boot of the spark plugs ... ..damn...

car has been waiting just too much. It is almost almost ready to see the streets again... and since i have clearance issues and my headers should fit better that head.. i were thinking on click the buy button again and this time ..get the other aluminum cylinder head...

but guess what... now it seems the head is a discontinued product... 5 years passed not in vain 

$350 is probably the cheapest way to get 'any' aluminum sbc heads assuming they are already runnable and don't need more work.  They are not especially good heads, but they are lighter! 

I bought a set of the $600 heads once. One of them literally wouldn't sit on the dowel pins. Of all the things to be wrong, you literally can't set it down on the block?! I massaged the dowel hole a bit and got them to sit down but then returned them anyway when I realized the TPI intake on the old C4 i was working on wouldn't even cover the 200cc intake port, and converting to carb or other intake wasn't an option for that car. 

I would try them again, but it has to be my car this time so i'm in total authority to do what it takes to get them to work. 

I think the intake you need will be labeled "87-95 centerbolt" . Rocker arms are different too vs older heads.