L-98 Head / Intake swap
Thread Starter
Racer
Joined: May 2006
Posts: 286
Likes: 0
From: Alpine California
L-98 Head / Intake swap
Hi Guys,
Bought the 87 I posted earlier about (It was just too good of a deal to pass on at $2500.00) with the blown headgasket / possible warped head. I'm still not sure if it's a good idea to try to machine a warped L-98 head, will probably just replace it. Talked to Chevy cause they were at a show I attended over the weekend, and the head GM Performance Parts is selling as a Vette replacement head is the ZZ4 aluminum head. Everything seems to be about the same, with one glaring exception, it has the '86' and earlier intake pattern! Chevy apparently no longer makes a head for the post '86' cars, you either have to convert to an earlier intake base or the vortec stuff. I pulled out my Chevy TPI fFuel Injection Swappers Guide, and it says that the '86' aluminum head motors had a lower intake base with the standard pattern that will fit with the Corvette rear mounted heat crossover set up, and that the casting # is 18436572. I tried to do a search on this (all the while thinking that # sounds familiar) and came up with nothing, before I realized that # happens to be a Small Block Chevy firing order. Does anyone know if this is an actual casting # or did they get confused by the firing order? Also looking at the Edelbrock 170 (Performer) and the AFR 180 & 190, with a TPIS Big Mouth lower and runners as a possible. I assume if I do this I would have to have a custom burned chip for the car, and to really take advantage of it, I might as well swap the cam as well while the entire top end is off, but I'm not sure I want to go that far yet. Any suggestions, comments, etc... Anyone running a similar combo, and if so, hows it run, how bad of a MPG hit did you take (with Gas Goging
the way it is here in San Diego, gotta consider that too now), etc... Thank's ,
Kurt
Bought the 87 I posted earlier about (It was just too good of a deal to pass on at $2500.00) with the blown headgasket / possible warped head. I'm still not sure if it's a good idea to try to machine a warped L-98 head, will probably just replace it. Talked to Chevy cause they were at a show I attended over the weekend, and the head GM Performance Parts is selling as a Vette replacement head is the ZZ4 aluminum head. Everything seems to be about the same, with one glaring exception, it has the '86' and earlier intake pattern! Chevy apparently no longer makes a head for the post '86' cars, you either have to convert to an earlier intake base or the vortec stuff. I pulled out my Chevy TPI fFuel Injection Swappers Guide, and it says that the '86' aluminum head motors had a lower intake base with the standard pattern that will fit with the Corvette rear mounted heat crossover set up, and that the casting # is 18436572. I tried to do a search on this (all the while thinking that # sounds familiar) and came up with nothing, before I realized that # happens to be a Small Block Chevy firing order. Does anyone know if this is an actual casting # or did they get confused by the firing order? Also looking at the Edelbrock 170 (Performer) and the AFR 180 & 190, with a TPIS Big Mouth lower and runners as a possible. I assume if I do this I would have to have a custom burned chip for the car, and to really take advantage of it, I might as well swap the cam as well while the entire top end is off, but I'm not sure I want to go that far yet. Any suggestions, comments, etc... Anyone running a similar combo, and if so, hows it run, how bad of a MPG hit did you take (with Gas Goging
the way it is here in San Diego, gotta consider that too now), etc... Thank's ,Kurt
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
They fit my '89 just fine so whomever you spoke to doesn't know what they're talking about or there's been a drastic change in the last couple of years or maybe I need to go verify my VIN. They come with LT4 springs and retainers and like the '91's, are counterbored at the front and rear manifold holes for the intake gasket retainers. You want the '91 Intake Kit GM 12525814. It's got the right intake and all the runner gaskets. See Gary at Mission Chevy (if he's still there) or Toni at Courtesy in Escondido. Both will knock a few Bucks off if you tell them it's for a Vette. Or you can order through Scoggins-Dickey for about a grand - $1200 or so ported.
Team Owner
Joined: Sep 2001
Posts: 62,119
Likes: 1,725
From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
Originally Posted by Blownfuel1
Talked to Chevy cause they were at a show I attended over the weekend, and the head GM Performance Parts is selling as a Vette replacement head is the ZZ4 aluminum head. Everything seems to be about the same, with one glaring exception, it has the '86' and earlier intake pattern! Chevy apparently no longer makes a head for the post '86' cars, you either have to convert to an earlier intake base or the vortec stuff. I pulled out my Chevy TPI fFuel Injection Swappers Guide, and it says that the '86' aluminum head motors had a lower intake base with the standard pattern that will fit with the Corvette rear mounted heat crossover set up, and that the casting # is 18436572.
ZZ4 should be a carbon copy of the '113 head.
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
"ZZ4 should be a carbon copy of the '113 head"
Check out a pic of a ZZ4 crate motor at any of the online sites ;
all have centerbolt covers exactly the same as the '89+ 113 head they are copied from
Check out a pic of a ZZ4 crate motor at any of the online sites ;
all have centerbolt covers exactly the same as the '89+ 113 head they are copied from
Thread Starter
Racer
Joined: May 2006
Posts: 286
Likes: 0
From: Alpine California
I "think" I found the answer last night, apparently, only Cast Iron Heads got the revised bolt holes in 1987, not the aluminum ones. If thats true though, then Corvettes and Camaro / Firebirds would use a different intake and I thought they were the same other than the EGR location. Thank's for the help guys.
