98 versus 99 heads
09-24-2002, 10:26 AM
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98 versus 99 heads What are all the differences in the 98 versus the 99 heads? I know the valve covers have the perimiter bolt pattern verses the 4 center bolts and that the coil packs bolt directly to the valve cover. Are coil packs the same between the two years? I have a 99 TA and I am considering buying a used set of heads off a 98 with the 98 valve covers and coil packs thrown in for free so I just want to make sure I know exactly what the differences are. Thaks for any help you can give me.
<small>[ September 24, 2002, 03:10 PM: Message edited by: Pro Stock John ]</small>
<small>[ September 24, 2002, 03:10 PM: Message edited by: Pro Stock John ]</small>
09-24-2002, 10:30 AM
#2
Re: 98 versus 99 heads All LS1 heads 97-03 are identical, with the exception of the bolt patter for the valve covers (as you mentioned) being center design after 98.
You will need the correct coil brackets that match the type of valve cover to mount the coil packs.
You will need the correct coil brackets that match the type of valve cover to mount the coil packs.
09-24-2002, 01:43 PM
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Re: 98 versus 99 heads No I believe the only thing you have to do is take the sensor off the 99 heads and put it in the same place on your 98 heads. There will be a plug L rench screw there remove it and put it on the passanger side far back hole on your 98 heads. They moved the sensor on the 99 to the drives side front side near the #1 piston. Make sure to put some silicone or gasket maker on the threads so the it wont leak on you.
09-24-2002, 02:14 PM
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Re: 98 versus 99 heads Thanks for the info.
Can anyone with 98 and 99 experience comment on how much more difficult it will be to work with the 98 heads verses the 99? I don't think it will be that bad but I would like to hear others opinions on this matter. Thanks
Can anyone with 98 and 99 experience comment on how much more difficult it will be to work with the 98 heads verses the 99? I don't think it will be that bad but I would like to hear others opinions on this matter. Thanks
09-24-2002, 03:08 PM
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Re: 98 versus 99 heads The heads internaly are the same I have a 99 TA and I put a set of 98 heads cuz I'm working on my stock 99 heads. Put big valves and opening up the ports and polishing u know the whole nine yards. The heads are the same just the bolt pattern on the valve covers. Even the coils form the 99 fit on the 98 all you have to do is take off the bracket, u can even use the same bolt to bolt them down.
09-25-2002, 12:39 AM
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Re: 98 versus 99 heads All you would need to swap over are the heads and valvecovers. The coilpacks themselves are the same. On the '98 heads they bolt directly to the valvecover. '99-up models have the coils on stamped steel brackets that bolt to the valvecovers.
Make sure you keep your coolant temp sensor from the driver side head, as the '98 sensor is different as well.
Make sure you keep your coolant temp sensor from the driver side head, as the '98 sensor is different as well.