OK,

Fun post here I am buying a 2003 XJR with low miles and want to pump up the HP.

I am in California.

I don't want the extra loud whine of a twin screw. If I could get 350+ hp at the wheels, that would be enough for me. What do these run at the wheels stock? I've heard around 300 rwhp, is this accurate?

What have you tried yourselves would you recommend, where to buy (each unit) and how much are they?

My somewhat uneducated/inexperienced ideas are to add:

Intake...should I just do the K&N and remove the sound reducing protrusions in the air filter box and remove the silencers coming off the intake tube between the air filter and the throttle body?

upper pulley to move power curve to lower rpms, or should I do lower, or both?

Does the $525 blower porting job upgrade from Eurotoys really give 20-30 RWHP??

which cooling upgrades to add/improve cooling

?does this 13 degree lower thermostat Jaguar Low-Temp Thermostat - Jaguar Performance Parts from Euro Toys work well, or does it cause problems with the computer thinking the engine is not at normal operating temp? I know I will still need to add cooling capacity.

Who has tried this killer chiller and is that what you would recommend or something else?

Water/alcohol injection?? Which unit? aquamist? I don't mind filling bottles of water.

Which ECU tune?

Which exhaust (cat back) ? I'm in California so I'll need to keep clean cats...would cutting out the front muffler and replacing with straight pipes work as well or better than x pipe?

Who sells these 3.58 geared rear ends and where / how much to buy?

Anything else??