• Fully Forged Aluminum LS3 376/416 CNC Square Port Long Block 1000/1200hp

Fully Forged Aluminum LS3 376/416 CNC Square Port Long Block 1000/1200hp

Blue printed New LS3 aluminum block Gen IV

CP Carrillo, Diamond or Wiseco shelf piston with GFX file fit ring

Steel ring set

K1 4340 forged connecting rods with ARP 2000 rod bolts

K1 forged crankshaft with reluctor 3.622" or 4.000"

King main bearings

King rod bearings

Thompson Motorsports single piece racing cam bearings

This short block is rated to 1000HP (1200HP with ARP main stud upgrade)

Frankenstein CNC Ported LS3 Cylinder Heads

Thompson Motorsports custom ground Camshaft

Billet adjustable timing set

GM MLS head gaskets

ARP Head Studs

Trunnion Upgraded Rocker Arms

Melling Select High pressure/ High Volume oil pump

Thompson Motorsports high RPM lifter set

GM lifter trays

Thompson Motorsports custom length Chromoly pushrods

Thompson motorsports Professional assembly and 12 month unlimited mileage warranty

For warranties and policies: https://www.thompsonmotorsports.net/warranties-and-policies.php  

***If, turbo, supercharged, or Stroker motor please add a High Pressure/High Volume oil pump for warranty"(if you do not add this pump for these application warranty will not be valid)***


*A crate is not required for a customer pickup, only an engine stand*


Call for any questions: 972-853-2450

We are located at: 

545 Justin Pl.

Nevada, TX



All motors could require minor modifications for install (drill and tap holes or clearancing). These changes are minor and can be performed with simple common tools. Thompson Motorsports is not responsible for the work required nor does this warrant a reason for the return of the product, even in the case of a direct replacement. We are dedicated to customer service and are more than happy to help with the install in any way possible. Please feel free to call or email with any questions or concerns.


 All high performance motors will come with no VVTI or DOD. If the vehicle originally had either or both of these you will need to change to a LS2 front cover and LS2 valley cover to eliminate. You will also need to alert your tuner to the changes for PCM changes.

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Fully Forged Aluminum LS3 376/416 CNC Square Port Long Block 1000/1200hp

  • Product Code: P-E4-18
  • Availability: 1000
  • $13,488.21

Available Options

Tags: TMS Longblock, Aluminum Longblock, Frankenstein, custom longblock