LT1 Block
Racer
Joined: Nov 2004
Posts: 445
Likes: 0
Originally Posted by lefoy84
The blocks all have the same casting numbers. The only way to tell if it's 2 bolt or 4 bolt is to look. The 2 bolt is still good for 400 HP plus.
I found this out after buying an LT1 thinking it was a vette engine, only to find out that it was for a Camaro, by virtue of its pre-fix ending in WTA.....
I was told that this meant that I had a two bolt main block.
If this info is wrong, I'd appreciate being corrected..
Large Impressive Member
Joined: Jul 2003
Posts: 65,811
Likes: 71
From: Good health is merely the slowest possible rate at which one can die
St. Jude Donor '04-'05-'06-'07
Originally Posted by CorvAdel
I was under the impression that the last three letters of the eng. no. pre-fix tells what type of vehicle the block was going in to. E.g. Corvette LT1's used ZAC, indicating 300hp, auto trans. motor, and ZUB 300hp manuals, in 1992.
I found this out after buying an LT1 thinking it was a vette engine, only to find out that it was for a Camaro, by virtue of its pre-fix ending in WTA.....
I was told that this meant that I had a two bolt main block.
If this info is wrong, I'd appreciate being corrected..
I found this out after buying an LT1 thinking it was a vette engine, only to find out that it was for a Camaro, by virtue of its pre-fix ending in WTA.....
I was told that this meant that I had a two bolt main block.
If this info is wrong, I'd appreciate being corrected..
Pro
Joined: Aug 2004
Posts: 623
Likes: 1
http://www.chevy-camaro.com/chevy-ca...es.asp?group=6
http://www.chevy-camaro.com/chevy-ca...?group=6BLOCKS
350 - There are two blocks, one with two-bolt mains and one with four-bolt mains. They both have the same 10125327 casting number, so there’s no sure way to know which one you have until you get the pan off. However, if it came out of a Corvette, it should be a four-bolt block, and if it came out of anything else, it was supposed to be a two-bolt. GM used the two-bolt block for everything but the Corvette because it had plenty of strength and it weighed a little bit less.
http://www.chevy-camaro.com/chevy-ca...?group=6BLOCKS
350 - There are two blocks, one with two-bolt mains and one with four-bolt mains. They both have the same 10125327 casting number, so there’s no sure way to know which one you have until you get the pan off. However, if it came out of a Corvette, it should be a four-bolt block, and if it came out of anything else, it was supposed to be a two-bolt. GM used the two-bolt block for everything but the Corvette because it had plenty of strength and it weighed a little bit less.
are they BIG BORE by any chance? I'd put myself down for one, even in cast iron. a 427+LTX would rock! 
Elite Torch Red Member
Joined: Sep 1999
Posts: 57,805
Likes: 23
From: Exit 89 GSP,Lakewood,NJ The Land Of Mojo
Cental/South NJ Events Coordinator
CI 1-2-3-4-5-6-7-8-9-10-11-12 Vet
CI-II Burnout & Drag Champ
St. Jude Donor '03-'04-'05-'06-'07
Originally Posted by CorvAdel
I was under the impression that the last three letters of the eng. no. pre-fix tells what type of vehicle the block was going in to. E.g. Corvette LT1's used ZAC, indicating 300hp, auto trans. motor, and ZUB 300hp manuals, in 1992.
I found this out after buying an LT1 thinking it was a vette engine, only to find out that it was for a Camaro, by virtue of its pre-fix ending in WTA.....
I was told that this meant that I had a two bolt main block.
If this info is wrong, I'd appreciate being corrected..
I found this out after buying an LT1 thinking it was a vette engine, only to find out that it was for a Camaro, by virtue of its pre-fix ending in WTA.....
I was told that this meant that I had a two bolt main block.
If this info is wrong, I'd appreciate being corrected..
1992=ZUB for manual trans
1992=ZAC for automatics
1993=ZVB for manual
1993=ZVA for automatic
1994=ZWB for manual
1994=ZWA for automatic
1995=ZUF for manual
1995=ZUC for automatic
1996=ZXD for manual(LT4)
1996=ZXA for automatic
all blocks were 10125327
Large Impressive Member
Joined: Jul 2003
Posts: 65,811
Likes: 71
From: Good health is merely the slowest possible rate at which one can die
St. Jude Donor '04-'05-'06-'07
Originally Posted by DieL
I've been speaking to a manufacturer to produce an aluminum LTx block for some time now. We're working out details on a prototype block that I may have by the end of the year
.. and its aluminum 
Originally Posted by Mr Mojo
From my sources, the LT1 suffixes are as follows:
1992=ZUB for manual trans
1992=ZAC for automatics
1993=ZVB for manual
1993=ZVA for automatic
1994=ZWB for manual
1994=ZWA for automatic
1995=ZUF for manual
1995=ZUC for automatic
1996=ZXD for manual(LT4)
1996=ZXA for automatic
all blocks were 10125327
1992=ZUB for manual trans
1992=ZAC for automatics
1993=ZVB for manual
1993=ZVA for automatic
1994=ZWB for manual
1994=ZWA for automatic
1995=ZUF for manual
1995=ZUC for automatic
1996=ZXD for manual(LT4)
1996=ZXA for automatic
all blocks were 10125327
Le Mans Master
Joined: Jan 2003
Posts: 8,596
Likes: 19
From: Portland Oregon
Ed, what are you looking to build? I have a seasoned LT1 F body short block in the shop that I can build a good foundation with. A two bolt block when you stud the main line caps are good for 500hp. Unless you plan on hitting it with NOS or supercharging it, there is no need to go with installing a set of splayed billet caps which will easily drive the cost of machine work and parts up another $1000. If that is what you want I would highly recommend Pro-Gram Engineering's billet main caps, these are of the highest quality and fit like a glove, plus they don't a problem with dip sticks fitting right.
