1994Vmax

iTrader: (4)

Stock to stock it's not even a race. The tuning in the 5.3 trucks is so pathetic it hurts haha. Tuned on premium with the 5.3 would be a drivers race against a stock 6.2 truck that runs well. But mod the old L9H and it pulls away again... I don't mind the direct injected stuff once you delete all the junk out of them... and I would start with an L86 myself. I have an L86 sitting here that needs a crank thanks to their splendid oil pumps.... might buy a 5.3 powered hoopty one of these days in the flavor I like and dump the 6.2 in it.

Bgbldodge

There is no replacement for displacement.

00pooterSS

iTrader: (40)

True, the ceiling will always be higher with more cubes.

I plan on doing a 6.2 swap some day for that reason. The DI 5.3 is really impressive, but there's only so much 325 cubes can do.

Bgbldodge

Wife gave me the go ahead to make the truck a hot rod so I’m looking for a 6.2 drop in but at the same time I’m debating getting a 5.3 and having it bored and built up because it’s so much cheaper to find. But then I’m at the cost of a drop in 6.2 but I’d have a built engine but I don’t see myself doing forced induction so a built bottom end would be wasted money. Factor all of this on to the fact this truck will have 200k miles by this time next year or sooner and it kinda makes all of it moot and I should sell it and get the AWD Denali I want.

ZO6Ted

I posted up where Hot Rod had an article that show an L83 made a hair more power than an LQ4 even on the low end. If it was me though I would definitely do the 6.2 with a cam.

Bgbldodge

I read that article. Pretty cool what technology can do. Direct injection was a game changer for the diesel industry. Kinda surprised it took gas engines this long to deploy it.

01WS6/tamu

iTrader: (36)

What was even cooler about the whole article is how maximized these new DI 5.3s are. The stock stuff works so good the normal bolts ons didn't hardly do anything for a power increase in comparison to the LS platforms.

arthursc2

iTrader: (5)

the only bolt ons worth a poo on the LS stuff are the intakes built by Garrett, Whipple, Borg Warner, ProCharger: etc

Everything else is a waste

Bgbldodge

They add cool noises to.

00pooterSS

iTrader: (40)

It's pretty impressive. When I pulled my exhaust off I was pretty impressed by the stock manifolds and y pipe, they aren't necessarily race car **** but they are damn good compared to the typical. The stock catback is a big area to pick up some power on the trucks though. The heads are are really impressive too, intake ports have a great shot to the valve (when I pulled my intake manifold off I was like well damn, okay then) they valve angle is like 11 degree IIRC (maybe 13 on the high side?) and canted valve on top of that. Also IIRC the 5.3 heads flow 280x cfm out of the box and the 6.2's do 33x. Intake manifolds are pretty damn good out of the box, big throttle bodies. And these motors have a crank scraper from the factory (I called Improved racing to order one and they said they don't make one because the gen 5's already have it). And these things make silly power. Texas speed sent me a dyno chart of a 6.2 bone stock except a mild cam, their stage 1, and it made 603 at the flywheel cam only.