Ls3 427
Thread Starter
Instructor
Joined: Mar 2008
Posts: 125
Likes: 0
From: Grand Island Nebraska
Ls3 427
I may have a chance to pick up a bare LS3 block cheap. I've been considering a stroker for my car and I'm looking for some input. I'm leaning toward a 402 LS2, but a 427 is much more appealing. I know I can get a stroker kit for an LS3 ,4.065" bore with a 4" stroke to make a 418 or 4.065" bore and a 4.100" stroke to make the 427. Although, from what I've read on CF that stroke seems to be less favorable, and I'm not trying to slam anyone with that stroke, I'm sure it works fine. My question is has anyone bore the LS3 to 4.125", the bore of the LS7. That combined with the 4" stroke will give me the 427 I'm looking for. It would require boring the block .060"...is that too much? I've looked for any info on a LS3 427 that this forum has to offer and there doesn't seem to be very much. I appreciate any info I can get.
BTW...I don't have the money for an LS7 swap. I know that'd be the best way to go.
BTW...I don't have the money for an LS7 swap. I know that'd be the best way to go.
Le Mans Master
Joined: Jan 2003
Posts: 8,596
Likes: 19
From: Portland Oregon
I may have a chance to pick up a bare LS3 block cheap. I've been considering a stroker for my car and I'm looking for some input. I'm leaning toward a 402 LS2, but a 427 is much more appealing. I know I can get a stroker kit for an LS3 ,4.065" bore with a 4" stroke to make a 418 or 4.065" bore and a 4.100" stroke to make the 427. Although, from what I've read on CF that stroke seems to be less favorable, and I'm not trying to slam anyone with that stroke, I'm sure it works fine. My question is has anyone bore the LS3 to 4.125", the bore of the LS7. That combined with the 4" stroke will give me the 427 I'm looking for. It would require boring the block .060"...is that too much? I've looked for any info on a LS3 427 that this forum has to offer and there doesn't seem to be very much. I appreciate any info I can get.
BTW...I don't have the money for an LS7 swap. I know that'd be the best way to go.
BTW...I don't have the money for an LS7 swap. I know that'd be the best way to go.
Drifting
Joined: Feb 2006
Posts: 1,349
Likes: 0
I don't understand aren't they basically the same block? There are ls2 427's all over the place that are resleeved and stronger than an ls7 427
Team Owner
Joined: Feb 2001
Posts: 27,231
Likes: 117
From: Short Hills, NJ
But I think what '02gt350' was referring to is what it takes to get to 427 when starting with an LS3 (or LS2) block. And as far as sleeving goes I don't anyone here even assumed you were referring to sleeving as a means to get there, just using a new crank (4" stroke) in an otherwise stock LS3 block which is how most now build a 416-418.
Sleeving is whole 'nother approach.
Team Owner
Joined: Feb 2001
Posts: 27,231
Likes: 117
From: Short Hills, NJ
I don't think that can be done safely, might thin out the cylinder walls/spacing too much.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
5 MOST and 5 LEAST Popular Corvette Model Years in History!
Joe Kucinski
Drifting
Joined: Feb 2007
Posts: 1,843
Likes: 12
From: Alpharetta Georgia
Former Vendor
Joined: Jul 2008
Posts: 223
Likes: 0
From: Upstate NY, South FL
A 4.1 stoke (which is too much IMO) will yeild 426. We don't go bigger than 4.0 in our LS3s
Yes, it absolutely is too much
Premium Supporting Vendor
Joined: Jan 2001
Posts: 17,681
Likes: 11
From: Central Jersey
Cruise-In II Veteran
Cruise-In III Veteran
Cruise-In V Veteran
If you have your heart set on an 427 use the LS7 block, if not you can easily do a 416-420 cu with an LS3 block. I would also stay with a 4 inch stroke no matter which block you end up with.
Le Mans Master
Joined: Nov 2005
Posts: 6,344
Likes: 22
From: Alexandria VA
Appreciate any feedback.
Moderator
Joined: Dec 2002
Posts: 40,877
Likes: 4,329
From: Lakewood Ranch, FL
Which is why I don't have a 427ci LS3
Le Mans Master
Joined: Nov 2005
Posts: 6,344
Likes: 22
From: Alexandria VA
I think the rod angles generated by the crank needed to bring it to 427 are a little much
Le Mans Master
Joined: May 2003
Posts: 5,362
Likes: 3
From: Delray Beach FL
I looked at the different options for stroker LS3 short blocks. I decided to go with a 418 with steel top rings. I use my 08 as a DD and for drag racing. I wanted the option to add power adders (NOS, Turbo, SC, etc.) and the 427 LS3 was not recommended for FI. Texas Speed offers both the 418 LS3 and 427 LS3. The 418 I am having installed is coming from TS. Maybe give them a call as well and discuss your options.
Burning Brakes
Joined: Jun 2008
Posts: 1,214
Likes: 3
From: CA
Doesn't the strength and dependability of the block also depend on how it was resleeved? ....Using dry or wet sleeves.
I've heard they have even bigger than 4.125 bores for the LS2/LS3 blocks and turn out to be much stronger than the LS7 block itself.
Correct me if i'm wrong though.
I've heard they have even bigger than 4.125 bores for the LS2/LS3 blocks and turn out to be much stronger than the LS7 block itself.
Correct me if i'm wrong though.
