Watch who tunes your car also. You don't want to blow the engine. Get a tuner that has some year in the business.

 

Bamaboy473, I grew up in Baldwin County and I'm dying to know what roads you're wringing your cars out on....I can think of a few fun ones...225 comes to mind, but it comes with a host of blind curves.

 

When I had fast bikes in Birmingham, AL, I'd take them out on Sunday mornings on 459; a 3 lane circular highway around town with great pavement and few cars. Several miles between exits allowed a good bit of comfort from cops, too, so flying along at 150-180 was both possible and safe. Baldwin County doesn't have that. Roads that can be used for power aren't all that long, so the launch process is the best I can find; hence a wish for the most power right Now...

 

If you want the most HP for the buck, I suggest that you save the money that you would have spent on a pulley and tune for your 4.2L XKR and put it towards a 5.0L XKR, and sell your 2008 XKR.

You might be content with the 5.0LSC stock 510HP, given the limitations of the roads in your area. Note that you can't get 600 HP out of a 4.2L XKR at a reasonable cost, but you can with a 5.0L XKR pulley, tune, and exhaust mods.

A 2010 XKR may be within your budget.
Car and Driver Road Test 2010 Jaguar XKR

 

A quick search came up with this gem, https://www.autotrader.com/cars-for-...ckType=listing

This is a woulda, coulda, shoulda kind of opportunity, Stuart. If I had known then what I know now, it would have been a no-brainer to get this cab over what I have. Can I justify keeping what I have? Sure, I like the coupe lines better, like the shift gate better, and all of the fixing has been done to it.

Were first year 5.0L as reliable as the 4.2 though? My wife's XJR has the 5.0L and so far it's been bulletproof, but it's a 2014; does that make a difference?

 

The 4.2’s infinitely more reliable and less costly to operate and maintain. There are only minor changes from 2010-2012 mostly with the timing chain and tensioners. The coolant system’s the weakest link on all version of the 3.0and 5.0 litre engines to date.

 

Good to know; I'll keep the money in the mattress then! Took a 1,200 mile trip up to Asheville and back a few weeks ago and the drive was flawless; a definite ride improvement over the Porsche, so that was a nice benefit.