Standard Features

  • Deck Height: 9.025” – 9.325”
  • Main Journal: 350 or 400
  • Cam Location: +.391“ Raised
  • Cam Journal: 55mm Roller  |  60mm Babbitt
  • Lifter Diameter: 904”
  • Bore Spacing: 4.400“-4.500”
  • Oil Pan Rail: Wide Pan Rail
  • Rear Main Seal: 1 Piece or 2 Piece

Forward Thinking

  • Core plugs are machined to accept -16 AN O-Ring style plugs. Core plugs are supplied with block purchase.
  • Oil galley plugs are machined to accept -6 O-Ring style plugs. Oil galley plugs are supplied with block purchase.
  • Lifter valley engineered to accommodate the majority of lifter locations.

Strength Beyond Compare

  • Industry leading cylinder wall thickness
  • Extended main stud bosses for additional thread engagement & added strength.
  • Extended head stud bosses for additional thread engagement. (Utilizes existing aluminum block head stud kits).
  • All 5 main caps 4-Bolt style caps.

Industry Firsts

  • GENII LT1 versions available.
  • Cooling Options: Standard or Reverse
  • Oil filter provision in conjunction with wide pan rail.
  • Priority main oiling with industry 1st “EQUAL FEED” lifter oiling.

The 1SPEC Evolution SBC cast iron block is a culmination of years of thought and development.  Some of the benefits to the Evolution block go unnoticed at first but once deep into the engine build you will come to find that this is truly the most advanced SBC block ever produced!

Each and every block goes through a rigorous quality control process to ensure that the final product is second to none!  Unique serial number tracking is used in conjunction with the QC process to track each and every detail on the block throughout the manufacturing process all the way through the shipping process!

Something as simple as oil galley hole locations holds a crucial roll in a blocks performance potential and is overlooked by the entire rest of the industry.  Since it does serve such a critical roll in the proper function of an engine we have spent countless hours in its design and engineering to ensure that it is exactly what the end user needs!  When designing a block to accommodate a wide variety of lifter manufactures, lifter diameters, lifter locations, cam heights, cam journal sizes, cam base circle sizes it becomes a major task to make a product that can adequately handle them all!  Other blocks on the market don’t even know that this is an issue, but we made it a priority!  Typically ,until the release of the Evolution block, if you tried to install a larger cam journal, a larger diameter lifter, a different lifter manufacture it was common to have the oil galley hole uncovered somewhere throughout the lifter travel (whether it be at full lift or on base circle) and the resulting problem was a temporary loss of oil pressure due to the lifter exposing the oil galley hole.  All 16 lifters doing this a 8000-10000 rpm….you can imagine the problems that can cause.  That is why we specifically spent so much time in correctly locating our oil galley feed holes to enable a wide variety of cam sizes, lifter diameters & manufactures, lifter bank angles and locations without the past problems of other blocks on the market!

The length and the way in which the cylinders of the block are machined are another aspect that is overlooked in the aftermarket block choices until now!   In todays offerings of crankshafts, and the large strokes available, it is important that the length of the cylinder bore be correct to enable the piston to be fully supported on the skirt throughout its entire travel….we have accommodated that!  This enables you to achieve those illusive HP numbers that other blocks cannot match!

Speaking of cylinder bores…….we also have engine building in our history so we know how important it is to be able to pull a product our of the box and use it without spending countless hours modifying and “rubbing” on it just to make it usable!  You machinists out there will appreciate this one:  we have gon to the extent of providing an under cut to the bottom of cylinders to enable the hone to simply stroke out when final machining your block!

Along the same lines of being user friendly…..we have actually gone to the extent of machining clearance in the front cover area to enable an engine builder to directly bolt on a belt drive without any additional machining or modifications!

Many advancements in world of fasteners have shown themselves over past few years.  We decided to engineer the Evolution block to take advantage of each and every one of them!  With the deep dive into how a fastener distributes its loads throughout the stud and the component it is engaged with, we have engineered and machined the Evolution block to take full advantage.  For example, we have machined a small relief in the deck of the block to allow the load to be distributed more uniformly throughout the fastener as it continues into the cylinder head.   With the same thought process in mind we designed the block to accept the longer “aluminum” style studs and precisely machine the blocks to take advantage of longer thread engagement and the bottoming boss on the stud to aid in a more uniform stress load distribution and repeatable clamping load throughout the entire length of available threads engaged in the block.