If you're a true believer in "bigger is better," then wave the flag for this Mouse, because it can't get much bigger than this. World Products has managed to cram a Rat motor 454 bore and stroke into a small-block and then twisted in a big enough cam to make some serious steam with mild heads and a single Holley four-barrel for induction.
The foundation is a World Products Motown iron block that stretches small-block boundaries with a 4.250-inch bore using Fel-Pro PN 1036 head gasket. The short-block reciprocates either JE or Wiseco forged pistons along with Scat or Eagle H-beam rods using a Scat 4340-steel forged crank.
Ironically, this major-league short-block isn't fitted with some exotic 15-degree cylinder heads. Instead, World selected a set of Motown 220cc, 23-degree valve angle heads complete with CNC-machined chambers and large-by-huge 2.125/1.60-inch Manley stainless steel valves. Top that off with a new Motown single-plane intake and you have a huge, yet relatively conservative, big-inch small-block.
The cam selection is easily the most aggressive component in this whole mix, but even at 252 degrees of duration at 0.050, you have to remember this is a 454ci engine! The flat-tappet cam is a solid choice since it keeps the price reasonable, and yet you can run more spring pressure than you could with a hydraulic.
While the price at $10,495 cannot be tagged as inexpensive, consider that along with this engine's pump gas-friendly demeanor is a warranty that offers coverage for up to 24 months or 24,000 miles. But we didn't come here to talk about warranties. Its time to go bolt this Maximum Mouse on the dyno and see what it's made of.
Cam Specs Camshaft Duration Duration Lift Lobe (Adv.) (@0.050) Sep. Crane mechanical Int. 290 252 0.560 112 Exh. 298 260 0.554 Parts Party Component Manufacturer PN Block, 4.125-inch bore Motown World Products 084021 Heads, Motown, aluminum World Products 024250-2 Intake, single-plane World Products 061040 Camshaft, mechanical, flat Crane 114691