ZZ4 Replacement Engine
Thread Starter
Intermediate
Joined: Aug 2019
Posts: 39
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From: Lethbridge
ZZ4 Replacement Engine
Hi Guy's:
Some may think this a stupid question, but I'd like to know what engine replaced the GM ZZ4 as I own an L48 in a C3, and would someday like like to change it out rather than replace the heads, intake, carb etc.
Tks,
Myles
Some may think this a stupid question, but I'd like to know what engine replaced the GM ZZ4 as I own an L48 in a C3, and would someday like like to change it out rather than replace the heads, intake, carb etc.
Tks,
Myles
Thread Starter
Intermediate
Joined: Aug 2019
Posts: 39
Likes: 0
From: Lethbridge
Late 60's Heads
Hi All:
Just a question. I also have a line on what is described as late 60's heads. The cast #'s are 3755550 & 3748770. I'm wondering if they would fit Chev Small block my L48
& are they of any use to increase engine output. The add states that they were previously on an engine with around 2000 mi that had been rebuilt.
Tks,
Myles
Last edited by Roentgen; Sep 5, 2019 at 04:54 PM.
Le Mans Master
Joined: Sep 2001
Posts: 7,739
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From: Unreconstructed, South Carolina
ZZ4 no longer in production ... neither are its 58cc aluminum heads cn 10088113 ... they're available used, but are becoming scarce.
Both 3755550 & 3748770 are Really Old iron heads ... they'll raise compression but that's about all.
ZZ4 was first replaced by ZZ5, then ZZ5 replaced by ZZ6 ...
... both ZZ5 & ZZ6 have aluminum heads with modern Fastburn (aka "vortec" or "heart-shaped") chambers
IMO ... You'd be much better served with modern Fastburn chambers & better-designed ports ... many manufacturers offer them.
Both 3755550 & 3748770 are Really Old iron heads ... they'll raise compression but that's about all.
ZZ4 was first replaced by ZZ5, then ZZ5 replaced by ZZ6 ...
... both ZZ5 & ZZ6 have aluminum heads with modern Fastburn (aka "vortec" or "heart-shaped") chambers
IMO ... You'd be much better served with modern Fastburn chambers & better-designed ports ... many manufacturers offer them.
