hydrolic144

iTrader: (2)

Did a little searching but didn't come up with much. I'm looking to replace the 87 L98 in my GTA right now. Came across a 90 L98 that's in a vette. Can hear it run before pulled and the guy is asking $500 for the complete engine. I know it has the aluminum heads. What issues or obstacles am I looking at by doing this swap? I read something about the EGR operating differently and that my TPI manifold may not bolt up with the 4 center holes correctly. That's about it. Anyone have any insight, is $500 a good price for it? Thanks.

88FormulaF_Bomb

iTrader: (1)

id pay 500 for a good set of those alum 113 heads sooo yea id buy it if everything is in order. as for your intake, your iron head 87 intake has a different bolt pattern then the alum head intake. so if the vette l98 doesnt come with one then id look into something aftermarket.


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88FormulaF_Bomb

iTrader: (1)

while u have the motor out of the car. you might as well wait to pull ur 87 l98 and build the 90 on the side to save time, money, and effort.


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BlackenedBird

iTrader: (5)

Your 87 has the same intake pattern as the 90 since it has center bolt heads. All you'd hafta do is swap the accessory drives over & possibly the oil pan & oil pickup, if the Vettes used a lower profile back then like it does for the LS engines, but I don't think that it does.

alex91z28

the corvette alum heads are angle plug must think of that if using headers with stock manifolds may not be a problem. now intake manifold pattern all bolts are 90 degree angle "old style sbc", you will need to use the corvette intake manifold. the intake has a egr valve feed hole on the back, you can just plug it up.

hydrolic144

iTrader: (2)

Forum has been wacky and just now seeing the replies. First off thanks everyone.

I'm considering this engine because the 87 has a rod knock and it's time to come out.

The engine will come totally complete. I think the guy said he was going to keep a pulley or two, but that's it. I didn't know it had angled plugs, that sounds like a good thing. I don't have any headers so hopefully I'll be okay.

According to the guy, the heads have been recondition and when he had them off, he saw either a .020 or .030 stamp on the cylinders. So it's possible it has been bored. Claims it runs like a raped ape. No leaks, smoke, ticks or knocks.

So looks like my only concern will be the oil pan and pump, and I also read that the Vette had a different EGR setup?

89L98TPI

The 113 heads have a angled plug. No benefit from plug angle. The 113 heads are a great upgrade over any Fbody head. GM still uses this head on crate motors to this day. As for oil pan yes the Vette had a specific pan and assume pick up as well. And EGR the Vette had a rear feed EGR off of the passenger side exhaust manifold. Eliminate it anyhow. Buy the whole motor and piece it together with what you have from your motor. Also you said motor was from 90 I believe. Thats a Speed density intake. your car is MAF.



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89L98TPI

Yes only corvette base manifolds from late 86-91 Vettes will work on 113 heads unless the 4 center bolt holes have been drilled out on the base manifold



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vetteoz

iTrader: (13)

When the SBC cast iron heads went to the centerbolt cover with the changed bolt angle on the 4 center bolts
the Vette alum heads kept the old bolt angle
Same as every other SBC head back to 1955

Any intake with reg SBC bolt angle will bolt straight up

Easily done with a file
Aftermarket intakes like the HSR come with 4 center holes slotted to either style head

vetteoz

iTrader: (13)

Correct
Have to use non Vette pan and reg SBC pickup
Sump on Vette pan is longer ( hits X member ) and shallower
OP is lucky both engines are 1 pce RMS so all his parts swap over

L98 one in pic is the Vette pan