ZZ4 in "85" ???????
Thread Starter
Pro
Joined: Dec 1999
Posts: 673
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From: Venetia,Pa,USA
ZZ4 in "85" ???????
What diffculties am I in for? I already know I need to buy a different flywheel because of 85 2 piece seal and ZZ4 one piece. Also will be buying a 11" 28 spline clutch/pressure plate. I installed a ZZ4 in my 91 without clutch differences. However I understand on the 85 the slave cylinder works opposite of the 91. One clutch release system pushes and the other pulls to release the throw out bearing. Do I need a special clutch/pressure plate or will the stock 91 type also work????
THANKS
THANKS
Melting Slicks
Joined: Jan 2009
Posts: 3,482
Likes: 196
From: folsom california
two of the differences are:
a later vette oil pan for a one piece rear seal; the factory zz4 pan is probably too deep for te vette chassis which uses a very shallow 7" pan;
a flywheel for a one piece seal crankshaft,
as long as the installed height of the new flwheel is the same as the original flywheel, and the transmission isn't changed, you should be able to reuse the original clutch without modification,
sounds like you have a very nice upgrade planned
a later vette oil pan for a one piece rear seal; the factory zz4 pan is probably too deep for te vette chassis which uses a very shallow 7" pan;
a flywheel for a one piece seal crankshaft,
as long as the installed height of the new flwheel is the same as the original flywheel, and the transmission isn't changed, you should be able to reuse the original clutch without modification,
sounds like you have a very nice upgrade planned
Thread Starter
Pro
Joined: Dec 1999
Posts: 673
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From: Venetia,Pa,USA
All your info is correct from what I found out today. I called Keisler who the tranny was purchased from to replace the 4+3 6 months ago. It fit like a glove. Now since the engine bit the dust and a replacement ZZ4 is coming I called them they have a kit for the complete change over. This isn't my car but a close friend.
THANKS
THANKS
Le Mans Master
Joined: Mar 2004
Posts: 5,107
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From: Dublin CA
From the research I did before putting in the ZZ4 in my 85 (automatic), the balancer should be changed to a 6-3/4" or you will have to cut or modify the crossmember.
I got my ZZ4 as a short block and then took it apart and had the assembly balanced before putting it back together. Using the short block I then used the Lingenfelter 74211 cam, my AFR 180 heads...etc. It is a much better setup that the complete ZZ4 long block.
You might think about putting a high flow water pump to replace the standard. This helps keep things even cooler.
I got my ZZ4 as a short block and then took it apart and had the assembly balanced before putting it back together. Using the short block I then used the Lingenfelter 74211 cam, my AFR 180 heads...etc. It is a much better setup that the complete ZZ4 long block.
You might think about putting a high flow water pump to replace the standard. This helps keep things even cooler.
Thread Starter
Pro
Joined: Dec 1999
Posts: 673
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From: Venetia,Pa,USA
Yea I know the damper needs to be replaced. I ran into the same problem when I put the ZZ4 in my "91".
George, yes it's Bob that you met at BeaveRun track about a month ago. He's trying to keep up with you on blowing engines. LOL
George, yes it's Bob that you met at BeaveRun track about a month ago. He's trying to keep up with you on blowing engines. LOL
