I have a new 09 GMC rcsb 4X4 that I ordered recently and will be arriving sometime in the fall. I am still pretty bitter about not being able to get the 6.2L in it considering it weights a slugish 5000lbs with all the options. With exhaust, header, computer, and air filter upgrades I can probably get it into the 350hp range. I am looking more for the 400hp - 450hp range or better. I think cylinder heads and cam will probably be my best option along with the bolt ons. Can anybody make recommendations to achieve this? I would like to still get decent gas milage and make the job as less complicated as possible. Please also let me know what upgrades I will need as a result of bigger power such as a high stall torque converter. The is a flex fuel option code LMG. Also fill me in on other options I may have considered unless they are an engine swap or a supercharger.

 

ok the first thing youre gonna want to do is a tune ... i reccomend charlie wheatley then youre gonan move on to bolt on's -intake, headers ,UD pulley , then if youre still not satisfied you're gonan have to go with a cam with just about any size aftermarket cam you get you should get at least a 3k stall ...

as far as cam's you can get a 212.218 or go witha proven cam such as a tsp 220 or tr 224 ... but thats as big as you wanna go witha 5.3 if u still want to have street manners

also welcome to the site , and remember in the future , the search button is ur friend

 

i dont think he will see 450hp wtih a 5.3(bolt on's ) . . . a 6.2 will solve all ur problems. . .

 

A heads/cam 5.3 could get 450 at the crank no problem IMO. I don't think he was talking about RWHP.

 

better go with a blower to keep streetability and get the kind of power you are after... gt2-3 and TVS1900 should do the trick.
450 rwhp with a 5.3 and bolt ons? good luck

 

good luck delivering those 450 on crank & getting them to the wheels.. with a 4x4 5000 lbs + +


these nnbs are f* heavy . .. ..

 

I know it won't get all that power to the wheels, but 450 at the crank is very respectable out of a 5.3L engine. Nobody could get 450rwhp out of a 5.3 without F/I, and even then it is hard.

 

true'true . ..

 

I thought the NNBS guys were seeing close to 340-350 before a cam?

 

Average ive seen on the dyno for a 4.8 with a tune is 260-280 and 290-310 for the 5.3s..