PappyDan

iTrader: (4)

go for a better stock cam out of an LS6.
1. has a lift of 500, in/ex LSA 115
2. has a lift of 525, in/ex LSA 116.5

replace the heads with a rebuilt set of 243's they will have the same size valves and ports, but come with a compression gain to increase power.

replace your stock 24 lbs injectors for a 8.1 set of 36 lbs.
long tubes, air filter, and a good tune should be pretty sweet for an
upgraded stock LQ4.

glengine

Does anyone on here know thw difference between the lq4 and the lq9?? I know that the pistons are different, but i've been told by one person that a bunch of other stuff is different and another guy told me that the rest is pretty much the same..

Parke10

iTrader: (5)

Uve asked this in two different threads ,i understand that you are new here but theres still no reason not to use the search button and to hijack threads

glengine

Sorry about that parke10 but i hadn't seen the other thread whn i poosted this one and the other one seemed much more applicable to my question.. And wasn't trying to hijack any thread.. Oh and by the way i never used the search button!

gold87TBI

iTrader: (12)

just get some bolt ons, my tow rig has all the bolts ons and a small cam 212/218 low lift, with 4.11 gears and i love it it is so fun to drive.

Parke10

iTrader: (5)

its alright i dont mind too much since everyone is here to helpa and give info, but if you do use the search button youll see 95% of yer questions you ever have,have been discussed and asked countless times.

glengine

Thats good to know.. thanks.

Thechevyman122

iTrader: (3)

having had both the 5.3l and the lq4 (orginnaly a z71 crewcab, and now a 03 denali) i can honestly tell you you will regret swapping in a lq4. no amount of mods in the world will the gas mileage of a lq4 anywhere close to that of a lightly modded 5.3l. The torque in a lq4 is great but i promise you if you dont think your 5.3 will tow it, it wont be that much more comfortable with the lq4. Anything that cant be town with the 5.3 needs to be town by the duramax. i have towed 10,000lbs when i had my 5.3 with no problems. Here is what you need to do:
Cold Air intake (i have had great success with volant and S&B)

Mild Cam, (you can get a custom grind or a z06 cam, springs, and pushrods for 250 bucks)

lt1 Electric fans (ebay for less than 100 bucks and harness made by derek@edo on this website for 75) *if your truck doesnt already have them*

A custom tune by wheatley, nelson, or blackbear (all of which are more expensive but far superiour to my wait4me etc)

Transgo Hd2 shift kit, with vette servo

freeflowing exhaust (ceramic long tube headers plus cats and muffler)

Of all these mods you are looking at way less time, money, and risk involved in a swap. you should pretty easily get 20 on the highway (with factory tire size and 3.73's) you will have much more "grunt" and will be able to tow alot. And you will be plenty fast, in case you ever do want to hot rod it.

I would start with cold air, headers, and a tune, Nothing internal and I nearly guarentee that will be make you love your 5.3 and wonder why you ever thought of a swap. and these mods will give you the gas mileage savings to compensate for premium. Even without premium, these 3 mods will make you wonder if you are driving the same truck