When it comes to building a big-cubic-inch LS, you have a couple of options. One of the more popular options is to start with the iron LSX block and go from there. But what if you don’t want the added weight of the iron block, but still want the ability to increase the displacement and handle relatively high cylinder pressures? Well, that’s when you would turn to Texas Speed & Performance for one of their new Darton sleeved Gen IV bare- or short-blocks.

“What we are doing is taking new Gen IV GM blocks and sleeving them with Darton’s dry sleeve and packaging them together in everything from a short block to a complete turn-key engine.” said Jason Mangum of Texas Speed and Performance. “That’s a brand new block with sleeves and studs and everything to support a lot of power for right around $2,000. With new GM blocks going up and up in price, it makes it a good option for the money.”

Mangum tells us that the new blocks can handle up to a 4.250-inch stroke due to the additional cylinder capacity provided by the 5.850-inch tall Darton sleeves. Combine that with a 4.165-inch maximum bore size and that means an LS engine well in excess of 460 cubic inches is easily accomplishable. Texas also offers built short blocks or turn-key motors in sizes ranging from 402 to 454 ci. 

“We are building and engine for a customer right now that uses a 4.250-inch stroke,” Mangum said. “The typical customer uses either a 4.00- or 4.125-inch stroke, but even then we see a lot of guys wanting it for the strength of the sleeve for their boosted applications.”

That makes this new mill the best of both worlds. You get the strength and rigidity that you need in a boosted application without incurring the 125-pound penalty that you normally would by going with an iron block. 

“Cars seem to be getting heavier and heavier for safety and this really helps combat those situations,” explained Mangum.

While it is hard to say what the blocks exact limitations are, Mangum told us that it has supported up to 1,000 horsepower without any issues. So, if you are looking to add big cubes, boost, or both to your build—and don’t want to add weight to your car—Texas Speed & Performance just might be your guys.