Need help with LS3 install
Thread Starter
Racer
Joined: Aug 2003
Posts: 348
Likes: 1
From: Sacramento CA
Need help with LS3 install
I'm having a clearance issue with the passenger side motor mount bracket. The LS3 has an extra bolt hole, and that is preventing my mount bracket from lining up. I have pictures attached. Suggestions please
Thread Starter
Racer
Joined: Aug 2003
Posts: 348
Likes: 1
From: Sacramento CA
thx for the help
Tech Contributor
Joined: Jan 2007
Posts: 19,493
Likes: 1,178
From: Dyer, IN
I know this will not be a popular response(knowing how some on this forum love to grind and hack).....but if that is you concern, then have it machined....so you don't have to worry about crack propagation.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Every 2027 Corvette Engine Explained
Joe Kucinski
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette
Verdad Gallardo
10 Ugly Corvettes That We Still Kinda Love
Joe Kucinski
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Le Mans Master
Joined: Jan 2009
Posts: 6,226
Likes: 33
From: Morton illinois
St. Jude Donor '14-'15
Le Mans Master
Joined: Jan 2009
Posts: 6,226
Likes: 33
From: Morton illinois
St. Jude Donor '14-'15
see on my above post. there is nothing it effects. ive done my 416, and a 440. both drag race, and on slicks, not the amature crap most do. 0 problems. AND...if it did break, you spend 80 bucks on a new one, and not grind on a multi thousand dollar motor. And to get that boss down far enough for the mount to fit, it would be dangerously close to getting way to thin
Tech Contributor
Joined: May 2008
Posts: 2,843
Likes: 16
From: Howell Michigan
St. Jude Donor '09-'10-'11
see on my above post. there is nothing it effects. ive done my 416, and a 440. both drag race, and on slicks, not the amature crap most do. 0 problems. AND...if it did break, you spend 80 bucks on a new one, and not grind on a multi thousand dollar motor. And to get that boss down far enough for the mount to fit, it would be dangerously close to getting way to thin
Still doesn't change the fact that cutting the mount bracket compromises more of the structure than removing the boss off the block. It’s not as scary 
as you might think.
Le Mans Master
Joined: Jan 2009
Posts: 6,226
Likes: 33
From: Morton illinois
St. Jude Donor '14-'15
ripping off the line would be the most dramatic force to it. and most here just go run on street tires is all I meant. But, to each their own!
Tech Contributor
Joined: May 2008
Posts: 2,843
Likes: 16
From: Howell Michigan
St. Jude Donor '09-'10-'11
Cliff, the LS3 Corvette engine mount, part #10349965 for the passenger side might work. The only issue that I'm not sure about is if the LS3 mount will or will not interfere with the a/c compressor mounting used with the LS1 configuration. I believe the mount list for around $80.
People have the choice to cut the bracket, remove the boss from the block, or go with a different mount. Any of these methods will get the job done and it becomes a personal choice. There may be aftermarket mounts that would add to the choices. For me, I would go with removing the boss off of the block, and maintaining the mount intact and save the $80.
Update: I did a little more checking, there should not be any issue with a/c compressor. In fact, changing to the LS3 mount might be the best choice.
People have the choice to cut the bracket, remove the boss from the block, or go with a different mount. Any of these methods will get the job done and it becomes a personal choice. There may be aftermarket mounts that would add to the choices. For me, I would go with removing the boss off of the block, and maintaining the mount intact and save the $80.
Update: I did a little more checking, there should not be any issue with a/c compressor. In fact, changing to the LS3 mount might be the best choice.
Last edited by Eric D; Dec 15, 2009 at 05:02 PM. Reason: Did some more checking.
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
Tech Contributor
Joined: May 2008
Posts: 2,843
Likes: 16
From: Howell Michigan
St. Jude Donor '09-'10-'11
