Rotating Assembly
Mondello upgrades components few builders even think of, from the use of its neoprene rear main seal (PN MS160) in lieu of the factory rope type or inferior aftermarket rubber seal to cryogenically treating the rotating assembly. The result is a bottom end well equipped to handle more than 750 hp.
Valvetrain
One area in which an experienced outfit like Mondello's paid big dividends is in the camshaft selection. Thankfully, companies like Comp Cams and Mondello aren't married to the convention that off-road guys simply need to stab in a little RV cam and enjoy off-idle torque. We're about power too. The Comp Cams billet solid roller was ground to Mondello's specs quickly and sent out the door in plenty of time for assembly and dyno schedules. Ground on a 110-degree lobe separation, the 268/276 at 0.050-lift cam features 0.640/0.649 lift and really brings out the upper-end power with hardly any bottom-end penalty. Believe in your builder. That's the bottom line.
Induction and Spark
Although we pushed Welfringer for specifics, we were unable to learn much more than the Edelbrock Torker manifold (PN 2730) underwent Mondello's proprietary blueprinting process. In a nutshell, the intake was port-matched to the cylinder heads using Mondello's gaskets and the plenum and ports were reworked to increase flow-a lot. Mondello also port-matched the Edelbrock Victor manifold (PN 2810) that we tested on Westech's dyno. The Victor was too macho for our engine, proving it needed even more compression, camshaft, and rpm to be happy. The Mondello-modded Torker proved to be an absolutely perfect match for the rest of the combo.
Mondello Pro Street 455 Build Sheet
Displacement: 468ci
Bore x stroke: 4.185 x 4.250 inches
Compression ratio: 10.75:1
Rod length, center to center: 6.735 inches
Piston deck height: 0.002-inch
Chamber volume: 77cc
Rod bearing clearance: 0.025-inch
Crank endplay: 0.004-inch
Piston-ring end gap: 0.014-inch (top), 0.018-inch (middle), 0.025-inch (bottom)
Piston-to-wall clearance: 0.005-inch
Camshaft type: Comp Cams solid roller
Valve lift: 0.640-inch (int.), 0.649-inch (exh.)
Duration at 0.050: 268/276 degrees
Lash (hot): 0.020-inch
Lobe separation: 110 degrees
Valve spring (seat): 250 pounds at 1.750-inch
The intake and exhaust ports are also treated to some CNC cutting as part of Mondello's valve job (right) to improve the flow numbers by 35 cfm as compared with out-of-the-box heads. The new port window matches the wide mouth of Mondello's Posi Flow intake gaskets. | 
Because a roller cam blank is made of billet steel, you need to run a bronze distributor drive gear. Performance Distributors built our DUI HEI with the right gear. The Comp Cams solid roller is a work of art, as are the Comp roller lifters. The solid cam required Mondello's TB740 thrust button as well as its brass (PN CS120-between the cam and block) and steel (PN CS40-behind crank gear) cam spacers to align the timing gear and crank gears | 
Mondello performed its Block Blueprinting process, which opens up the oil holes and returns, smoothes any rough edges that hamper oil flow, and installs its oil restrictors. |