Did '89 L98s come with hardened guideplates stock?
06-10-2003, 03:30 PM
#1
Drifting
Thread Starter
Did '89 L98s come with hardened guideplates stock?
This may get a little long, so bare with me for a sec...
I'm asking the above question because I discovered last night that the Comp Cams 1.6 ratio Magnum roller-tipped Rocker Arms that I installed on my '89 L98 not too long ago are NOT self-aligning. I've been told through another discussion thread on the forum that in order to use these rocker arms I'd need to use hardened pushrods and hardened guideplates. So I'm weighing my options. The way I look at it, I can either:
A) reinstall my original stamped self-aligning rocker arms and sell these Magnum roller-tipped rocker arms - by far the cheaptest option
B) get the correct self-aligning 1.6 Magnum roller-tipped Rocker Arms from Comp Cams (set #1418-16 BTW) and install them using my old pushrods and guideplates - more expensive than A but a bareable expense since I would still sell the non self-aligning set of roller-tipped rockers
C) get hardened pushrods and guide plates but stick with the non self-aligning roller-tipped rocker arms - an option I don't want to do, but it's there
D) do the job right and get not only the correct self-aligning 1.6 roller tipped rocker arm set, but also the hardened pushrods and hardened guide plates - the most expensive option
I don't mind going with Option D even though it's the most expensive of the 4 choices. However, while trying to price-out a set of hardened guide plates and hardened purshrods I came across something interesting...
It is my understanding that as of 1987, GM introduced self-aligning rocker arms on the L98 as a means of eliminating the need for hardened guideplates and hardened pushrods. As a result, the pushrods in the L98 where supposedly not hardened; hardened guideplates where installed on aluminum 128 castings, but not on the 113s (althouth they did have guideplates they were reportedly not hardened units, and only used for engine assembly purposes).
So I was looking through the GM Performance Parts catalog to get a sense of what hardened pushrods and hardened guideplates are available from GM. This is where things get a little interesting. The only hardened guideplate I found for aluminum heads is part number 14011051 which is a hardened guideplate made for aluminum Bow Tie heads. The Technical Notes for this part state: This guideplate is identified by the stamped number "05". When I pulled the valve covers off of my engine last night, I notice that all of my guideplates have the number "05" stamped in them!!! What gives?
So now I ask the question: did L98s with 113 aluminum heads originally come with hardened guideplates or not?
P.S. Sorry for the long winded story...it happens when I get excited about discovering something new.
I'm asking the above question because I discovered last night that the Comp Cams 1.6 ratio Magnum roller-tipped Rocker Arms that I installed on my '89 L98 not too long ago are NOT self-aligning. I've been told through another discussion thread on the forum that in order to use these rocker arms I'd need to use hardened pushrods and hardened guideplates. So I'm weighing my options. The way I look at it, I can either:
A) reinstall my original stamped self-aligning rocker arms and sell these Magnum roller-tipped rocker arms - by far the cheaptest option
B) get the correct self-aligning 1.6 Magnum roller-tipped Rocker Arms from Comp Cams (set #1418-16 BTW) and install them using my old pushrods and guideplates - more expensive than A but a bareable expense since I would still sell the non self-aligning set of roller-tipped rockers
C) get hardened pushrods and guide plates but stick with the non self-aligning roller-tipped rocker arms - an option I don't want to do, but it's there
D) do the job right and get not only the correct self-aligning 1.6 roller tipped rocker arm set, but also the hardened pushrods and hardened guide plates - the most expensive option
I don't mind going with Option D even though it's the most expensive of the 4 choices. However, while trying to price-out a set of hardened guide plates and hardened purshrods I came across something interesting...
It is my understanding that as of 1987, GM introduced self-aligning rocker arms on the L98 as a means of eliminating the need for hardened guideplates and hardened pushrods. As a result, the pushrods in the L98 where supposedly not hardened; hardened guideplates where installed on aluminum 128 castings, but not on the 113s (althouth they did have guideplates they were reportedly not hardened units, and only used for engine assembly purposes).
So I was looking through the GM Performance Parts catalog to get a sense of what hardened pushrods and hardened guideplates are available from GM. This is where things get a little interesting. The only hardened guideplate I found for aluminum heads is part number 14011051 which is a hardened guideplate made for aluminum Bow Tie heads. The Technical Notes for this part state: This guideplate is identified by the stamped number "05". When I pulled the valve covers off of my engine last night, I notice that all of my guideplates have the number "05" stamped in them!!! What gives?
So now I ask the question: did L98s with 113 aluminum heads originally come with hardened guideplates or not?
P.S. Sorry for the long winded story...it happens when I get excited about discovering something new.
