[blight]

So from advice from a people here and other venues, as well as a ton of reading it looks like for my setup the l98 heads are the best choice. My deal now is that I am having a difficult time distinguishing the differences in the many types of L98 heads.

----------------------------
there was;

On the firebirds/camaros
iron 305 heads from 85-86
iron 305 heads from 86-89

iron 350 heads from 87-89
iron 350 heads from 90-92

on the corvette
iron 350 heads from 84-86
aluminum 350 heads from 87-89
Aluminum 350 heads from 90-92
-----------------------------

This gives me waaay to many choices.
This is for an old style intake and I am unclear if I can use the 87 and newer style heads for one, and to be blunt what they all flow like and their valve size and combustion chamber size.

Can someone shed some light on these for me?

[RippinRon]

The l98 was a tuned port injection (TPI) 350 that came in 86-92 vettes and some f-bodie. They were aluminum.

[blight]

they were not all alum, and the 305s in the camaro/firebirds were iron. i think it may have been a rare option for the 350 camaro/firebirds from 87-92 to get alum.

[RippinRon]

The 305 is not a l98, the vettes were aluminum and the sought after l98 heads that people are generally after is the aluminum ones.

[DoubleVision]

Where you get there was a L98 305? When a engine line is given a RPO the cubic inches don`t change as that would create all kinds of confusion.
As Ron said far as I know only the corvette got the aluminum L98 heads.
I dunno where you got your info from, but make sure and tell`em it`s wrong.
Quick edit, I have seen one IROC have the aluminum heads, that was because someone transplanted the engine out of a totaled corvette

[blight]

http://www.hotrodlane.cc/PDFFILES/TPIStory.pdf

http://en.wikipedia.org/wiki/Chevrol...l-block_engine

http://www.thirdgen.org/techboard/tb...-headflow.html

[DoubleVision]

And your point is? I just looked over the links you gave and they all say what`s already been said. 193 and 197 casting heads are swirl port heads. The wiki article shows the L98 listed under the 350 and many codes were used on various performance engines from L48 to LT-1.
The L98 was only avalible with tuned port injection and these are the casting numbers used:
14101128 350, Corvette, 86-87, alm., angle plug, 58cc
14011083 350, Camaro 87-up, 64cc, center bolt VC, 72º manifold bolt

[blight]

no point - just the info is just not entirely clear to me it almost looks scattered im a spreadsheet kind of person.

[DoubleVision]

Allrighty then. However, if your curious to learn then just look up small block head casting numbers. Even so I looked at the links you gave I didn`t get confused at all as no where did it say there was a L98 305 head. It did say LO3 305, which is what it`s RPO code was. To break it down even more, lets look at the avalible engines for the late 80`s early 90`s F body line. The TBI engines only came with swirl port heads, which are horrible flow wise due to the huge swirl vane in the intake bowl. The 305 TPI engine came with 081 casting heads, it`s RPO was LB9. Here is a page that shows RPO`s and there relation to cubic inches and power ratings:
http://www.iroczone.com/2009/10/1989...pecifications/
Quick edit, I take it your looking for a set of heads, I`ll be happy to recommend them, just tell me your engine`s combo and don`t leave out the details.

[F-BIRD'88]

The L98 heads are "083" (cast iron) and 113 or 128 (aluminum )
The L98 motor is a 350 not a 305.

The 305 TPI motors are different and use different heads. (with smaller valves and chambers (4416 or 081)

The stock L98 heads (both 083 and 113) in stock as cast form have modest air flow (just under 200cfm)

But they come right up with full porting and larger valves.
Use 2.00x 1.56" "LT-4 " style valves for max perf w porting.

Short of the vortecs (906 062), these are the best recent stock OEM SBC heads TO PORT. 260 to 270cfm is possible. and well over 200cfm ex.

The cast iron L98 heads come with odd angle on the center 4 intake bolt holes. Stock SBC manifolds bolt holes can be elongated to fit.
Ports are the same. The aluminum 113 castings have standard intake bolt pattern.

They need quite a bit of porting but turn out very well and make very good power when all done.

Stock as cast form ='s modest airflow and horsepower.
Unless you get hem dirt cheap and can rebuild them dir cheap and port them yourself buy aftermarket high perf heads. Like Brodix IK180 or IK200.