Can you build 427 c.i. using an iron 6.0L block?
Thread Starter
Teching In
Joined: Nov 2006
Posts: 13
Likes: 0
Can you build 427 c.i. using an iron 6.0L block? Can the 6.0L iron block be bored and stroked to produce 427 cubic inches? If not, what is the most cost effective block/bore/stroke combination to produce a 427?
12 Second Club
Joined: Mar 2006
Posts: 302
Likes: 1
From: Sarasota, FL
A 4.060 bore and 4.125 crank produces a long-stroke 427. A 4.080 (L92) bore and 4.100 stroke gets a 429. Whether these are the most cost-effective ways to go is another question. You're either going to spend money on a C5R or sleeved block or on a over-4" stroker crank and custom pistons.
Texas Speed lists a 4.100 Eagle crank at the same price as a 4.000, $900. Combine that with a 4.060 LQ9 block and you get 424.6. Close enough? The disadavantage is that I believe you'll need to spring for custom pistons, so that's a few hundred extra.
The 4.00" stroke appears to be very popular with LSx engines, the larger strokes much less so. I suspect there are good reasons for this having to do with block deck height, compression distance, etc.
Texas Speed does a 418 4.080x4 L92 shortblock for $4755. Katech has their value 4.125x4 sleeved 427s for a bit under $7k. I doubt it can be done much, if any, cheaper than either of these packages. You might call TSP and ask about a L92 block with the Eagle 4.1 crank and custom pistons for 429cid. I'm going to guess at around $5200. If you do, please post results; I'm interested myself.
Texas Speed lists a 4.100 Eagle crank at the same price as a 4.000, $900. Combine that with a 4.060 LQ9 block and you get 424.6. Close enough? The disadavantage is that I believe you'll need to spring for custom pistons, so that's a few hundred extra.
The 4.00" stroke appears to be very popular with LSx engines, the larger strokes much less so. I suspect there are good reasons for this having to do with block deck height, compression distance, etc.
Texas Speed does a 418 4.080x4 L92 shortblock for $4755. Katech has their value 4.125x4 sleeved 427s for a bit under $7k. I doubt it can be done much, if any, cheaper than either of these packages. You might call TSP and ask about a L92 block with the Eagle 4.1 crank and custom pistons for 429cid. I'm going to guess at around $5200. If you do, please post results; I'm interested myself.
Actually, the long strokes are becoming much more popular these days. I wouldn't run longer than a 4.125" on a stock sleeve/iron bore legnth, but it can be done. Personally, I would do a 4.060" x 4.100" if I were working with a iron block. This will keep the cost at bay. Pistons won't be but $100 to $200 more than the average shelf piston. I'd say the iron 425 could be done for less than $4500.
i would love to go bigger cubes, but resleeving a block costs an arm and a leg. i want to go bigger but there seems to be no cheap way of doing it, the 408 from TSP seems to be the best for the money.
it sucks that cheap, reliable, and fast cant all go together
it sucks that cheap, reliable, and fast cant all go together
Originally Posted by JDP
i would love to go bigger cubes, but resleeving a block costs an arm and a leg. i want to go bigger but there seems to be no cheap way of doing it, the 408 from TSP seems to be the best for the money.
it sucks that cheap, reliable, and fast cant all go together
it sucks that cheap, reliable, and fast cant all go together
Registered User
Joined: Apr 2022
Posts: 1
Likes: 0
From: Virginia
there is no such thing as a 6 liter block because the liters consist of bore and stroke, so the block can be any liter with in that range, a few over or under .. but only a few like 6.3 or 5.8 liters ..
It's called a poor mans LS7 but certainly not something recommended. First off your over boring the 6.0 block and the cylinder walls will become too thin. If the block was sonic tested and you could take it .060 over and with a 4.10 crank you'd have a 425. It's best to not go over .030 on the bore and build a more reliable engine though.
Trending Topics
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?
Pouria Savadkouei
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Verdad Gallardo
7 Most Reliable High-Performance Engines GM Has Ever Built
Verdad Gallardo
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin
Verdad Gallardo
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
TECH Senior Member
Joined: Jun 2016
Posts: 22,300
Likes: 3,625
From: Central Cal.
GM can do this because except for the 4.8 and LS7, all LS engines use the same stroke crank.
It's called a poor mans LS7 but certainly not something recommended. First off your over boring the 6.0 block and the cylinder walls will become too thin. If the block was sonic tested and you could take it .060 over and with a 4.10 crank you'd have a 425. It's best to not go over .030 on the bore and build a more reliable engine though.
TECH Fanatic
Joined: Jan 2009
Posts: 1,075
Likes: 479
From: Bostwick, GA.
Huh?? 
TECH Senior Member
Joined: Jun 2016
Posts: 22,300
Likes: 3,625
From: Central Cal.
Last edited by grinder11; Apr 8, 2022 at 10:02 AM.
That has to be one of the most ignorant things I have ever heard....ever....
@CM1Magnus seems to have breathed life back into into this 14 year old thread with his single post...and hopefully learned some in the process.
