Generation III Internal Engine 1997-2006 LS1 | LS6
Sponsored by:
Sponsored by:

Question on Crate Motors

Thread Tools
 
Search this Thread
 
Old Jun 7, 2009 | 10:22 AM
  #1  
jct404's Avatar
Thread Starter
Teching In
 
Joined: Jun 2007
Posts: 8
Likes: 0
Default Question on Crate Motors

I've been looking at some performance crate motors to swap out my current motor. I have a 496 w/allison in a 3/4 ton right now and want to put a higher HP crate motor in its place, either another 496 or maybe a 502. My question is are they going to be the same block (bolt patterns) or are these crate motors an older version to the L18. I am going to call a couple places monday but I thought I would get a jump on it today. Programing will not be am issue for I have EFI live.

Thanks, Jon
Reply
Old Jun 7, 2009 | 04:56 PM
  #2  
Shawn MacAnanny's Avatar
TECH Addict
iTrader: (12)
 
Joined: Jul 2004
Posts: 2,105
Likes: 3
From: Delaware
Default

Keep in mind the Allisons MAXIMUN input shaft rpm is 4800rpm. Atleast thats what its rated for. I have a Duramax/Allison. This Gen3 forum is for LS1 series engines. They are on an SBC format, your 496 is a BBC format and not compatible with much. Has a different firing order than BBC, but from what i understand with a little tuning can be made to run a BBC cam from what ive heard. Read the conversions and hybrids forum there are a couple threads with info on them.

The bolts pattern will be the same. The allison trans has a BBC/SBC bolt pattern believe it or not, even on the Duramaxes. The only difference will be the crank spacing. I am unsure of the crank spacing with the 496/allison
Reply
Old Jun 9, 2009 | 06:22 PM
  #3  
jct404's Avatar
Thread Starter
Teching In
 
Joined: Jun 2007
Posts: 8
Likes: 0
Default

Thanks Shawn, I guess my main concern would been the EFI bolting up, Alot of the motors I have looked at are pre 1976 emmisions...so I wasn't sure what they were meaning.

Yeah I have read about the 4800 +/- rpm deal on the allison its got alot to do with the torque converter. I'm not out to have a big block turning 6k, just good low to mid range power.

I'll go dig in the other forum. Thanks again.

Jon
Reply




All times are GMT -5. The time now is 01:58 AM.

story-0
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-1
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-2
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-3
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-4
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-5
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE
story-6
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE
story-7
Awesome K5 Blazer Restomod Comes With C7 Corvette Power

Slideshow: A heavily reworked 1972 K5 Blazer swaps its off-road roots for a low-slung street-focused build with modern V8 power.

By Verdad Gallardo | 2026-03-09 18:08:45


VIEW MORE
story-8
10 Camaros You Should Never Buy

Slideshow: There are thousands of used Camaros on the market but we think you should avoid these 10

By | 2026-02-17 17:09:30


VIEW MORE
story-9
10 LS Engine Myths That Refuse to Die

Slideshows: Which one of these myths do you believe?

By Verdad Gallardo | 2026-01-28 18:10:11


VIEW MORE