“We developed this sleeved block for our 427 crate engine package and now we are offering it to the public for your own build,” says Katech Director of Aftermarket Operations Jason Harding. “It maintains an optimal bore/stroke ratio for high-revving performance and excellent durability. And with stronger sleeves than the originals, you can add power with the confidence the block will stand up to the pressure.”
To produce this robust engine block, Katech takes a brand-new, aluminum LT1 block and removes/replaces the factory cast-iron cylinder liners. Those liners, which feature a 4.06-inch bore, are swapped out for a set of centrifugally-cast ductile iron liners made-to-order, either rough-bored to 4.120 inches, or finish-honed to 4.125 or 4.130 inches.
With an approximate tensile strength of 120k psi, the ductile iron sleeves flex more than the more-brittle original liners, which helps prevent cracking under very high cylinder pressures. Additionally, the bottoms of the sleeves are machined to allow the use of a 4.000-inch stroke crankshaft. With 4.125-inch bores and a 4.000-inch stroke, the enhanced LT1 block delivers the same dimensions as the previous-generation LS7 to create a 427-cubic-inch (7.0L) displacement.
Additional features of Katech’s sleeved LT1 block include:
- Double vacuum-impregnated
- Surface decked
- Camshaft bearings installed
- Machined for piston squirters
- Ships in a plastic tote (sold separately)
The block is listed on Katech’s website for $3,699.99. To place your order, or learn more information, click here.
Don’t forget to check out Katech’s other Gen V LT1 offerings, including the valve covers and coil relocation kit.