I checked the Screaming Eagle Pro Parts Catalog for 2006 and found out the following information.
Screamin' Eagle Pro "Bigger-Bore" Cylinder Kit (Page #45)
Part # 16551-04 (Silver Highlighted) Pair $439.95
These 4.060 inch "Bigger Bore" cylinders increase the displacement of a Twin Cam 88 engine from 1450cc to an incredible 1856cc (113"/1.9 Liter) when paired with the Screamin' Eagle Pro Stroker Flywheel & Rod assembly. Cylinders are factory-honed to accept standard bore size 4.060" pistons. Cylinder spigot is machined for cylinder-to-cylinder clearance for this large displacement application. Installation requires crankcase machining by a qualified machinist. Dealer installation is recommended. Kit includes front and rear cylinders and required gasket. For race application only.
Fits '99 later Twin Cam equipped models. EFI models require ECM recalibration through applicable calibration cartridge or through EFI Race Tuner Kit. See EFI Race Tuner Kit for fitment or calibration matrix for possible applications.
113 C. I. Bigger Bore Pistons (Page #47)
Part # 22545-04 Standard Bore (pair) $279.95
Fits '99-later Twin Cam models equipped with Screamin' Eagle "Bigger Bore" 4.060" Cylinder Kit, Screamin' Eagle HTCC or Ported HTCC Cylinder Heads and Stroker Flywheel and Rod assembly. EFI models require ECM recalibration through applicable calibration cartridge or through EFI Race Tuner Kit. See EFI Race Tuner Kit for fitment or calibration matrix for possible applications.
Screamin' Eagle Pro Twin Cam Ported "HTCC" Heads (Page # 42)
Part # 16934-02B (Silver Highlighted) $1,299.95
These heads have been updated with the '06 intake flange geometry and will accommodate the Screamin Eagle Pro 50mm EFI Induction Module. Kit includes revised intake flanges, intake seals, and required hardware. This head is for serious performance engine builders, and is the highest-flowing cylinder head available from Screamin' Eagle. This high flow CNC ported version of our popular "HTCC" head has a 2.0' intake valve, 1.623" exhaust valve and 84cc combustion chamber volume, and ports designed to produce big horsepower. This head is fitted with valve springs capable of withstanding .650' lift and revs up to 7,000 RPM. Use with Screamin' Eagle Intake Manifold P/N 29635-99. Heads are machined to accept Compression Release Kit P/N 32076-04. For race application only.
Fits '99-later Twin Cam models equipped with Big-Bore Cylinders. EFI models require ECM recalibration through applicable calibration cartridge or through EFI Race Tuner Kit. See EFI Race Tuner Kit for fitment or calibration matrix for possible applications.
Screamin' Eagle Pro 50MM EFI Throttle Body (Page # 29)
Part # 27623-05 $399.95
Higher flowing for larger displacement race engine applications. Includes fully assembled throttle body and unique intake flanges and seals. This big bore throttle body features a 50mm throttle plate (a 4mm increase over the '06 Original Equipment throttle body) to provide increased airflow, and more power. Higher flow rate injectors provide increased fuel delivery to complement the increased airflow. Sensors, injectors, and the IAC stepper motor are fully assembled on this bolt-on unit. Recalibration is required through EFI Race Tuner or applicable performance calibration cartridge. This is not cruise control compatible. For race application only.
Total Cost of Parts - $2,419.80
Note - Only down side that I can see is you would loose your cruise control capabilities [smiley=disappointed.gif]