After more power 4.2 carby dual fuel

[Bigrig]

OK then. start again.
After more power from 4.2 carby lwb 4x4 on dual fuel, this is a highway cruiser tow vehicle, daily driver.
Has all the usual mode so far.
Extractors, 2 1/2 exh system, pertronic, iridium plugs, morey's oil drip system.
2" raised and poly bag inside rear, caster correction etc.

After a power increase to tow so where not that 4x4 that hold everyone up at the first sign of a hill.
So approx 30% increase in power could be on the money.

After advise from someone that know's on what can be used to achieve a reliable engine for this sort of gain in power and the added torque.
Think v8 is over kill on cost and that this sort of power gain can be easy to achieve with efi cam and maybe turbo. And not interested in diesel.
$$$$ are not the question here I'm after the info.
Just to quote cam, injection, turbo , isn't a answer.This is obvious.
What has been done and or can be used, and parts spec's to achieve this sort of gain with reliability.
After the complete story for around 30% increase in power and the associated torque that goes along with it.

Cheers

I think whatever way you'll go, you'd end up with at least 30% power increase with the ability to have more (i.e. low boost turbo = 30%; higher boosting = ??% possibly up to and over 100% even). A basic turbo kit (chinese ones which is what I have) and gear will probably be a decent start if you're only looking for low to mild boost (5-7 pounds) to get rid of the rigs fear of anything slightly uphill. Adding an intercooler to it is absolutely not necessary at that sort of boost, so that is a major cost saving straight away - turbo/wastegate/actuator etc; manifold, dump pipe, sump modification for oil line, etc I reckon you could get your hands on for under a couple of thousand at the very worst. For fitment of that to the rig, you should only be looking at the same (or considerably less) through a decent mechanic and you have the desired outcome for a fairly economical price - with the ability to kick it up in the future if you should decide to do so.

Brands etc are not something I know, but that would be the place to start - basic kits ... QuickSpool do a proper Garrett bolt on kit for the Patrols starting at $3999 and they achieve around 480hp!!!