[eschaider]

Mike,

SPF modified the chassis sometime prior to my chassis which is 2291. I believe the change involved moving the steering slightly outboard to clear the engine. When I got mine in 2006 the only modular motor SPF had headers for was the 4.6, that may have changed since then to include the 5.4. You ought to check before buying engines or engine pieces.

You will find that a Whippled 4.6 with moderate boost in the 16 -17 psi area produces about 600 RWHP by 6000 rpm which is gigantic in one of these chassis. To help put RWHP in context to FWHP divide by ~.85 which means the 'little' 4.6 is somewhere around 700 FWHP or possibly slightly more.

The most important consideration from a seat of the pants driver's point of view however is torque. The Whippled version of the 4.6 produces between 550 and 600 ft/lbs of torque from below 2000 rpm, depending on how you have tuned it. This can be difficult to hook up if you are not prepared and equally difficult to manage in turns if you are not careful.

I am not sure that a 5.4 makes a lot of sense partly because of the power available from the 4.6 and partly because you will find yourself using a lot of FGT 5.4 pieces which are staggeringly expensive.

Ed