Those of you that are running a 5.3L... Do you like the power it makes? I'm trying to decide whether to bore mine out to a 347ci and make it a cast iron LS1 or to drop some flat top pistons in and leave it the factory bore. Either way I'm going to add a heads and cam package. I just wonder what the realistic power gains would be from keeping it the stock 325ci while upping compression and adding a top end on it. Or... buying a set of LS1 pistons and boring it out.

And yes, I know a 6.0L would make more power and a actual LS1 is lighter. lol.. I asked this question on LS1tech.com. Got some good feedback and got some of those comments as well. But I have this complete 5.3L and I'd like to make something of it.

I know what a heads and cammed LS1 feels like from owning a M6 2001 SS Camaro. But I've never had a built 5.3L in a car. Just looking for some opinions from those that have made this swap with some mods.

 

You can make plenty of power to touch high 11's with a 5.3 in a good setup car. Ported 5.3's and mid 220's cam is very fun. I have seen a local kid do a cam only 4.8 in a 4th gen that went 12.2 at 112-114 or so

 

If it were mine, I'd only bore it out if the cylinders really needed it. Otherwise you are spending money on pistons and rings that aren't really needed.

 

I've seen (and even bought) an LS1 shortblock minus sensors and pan for $700-800. Its not worth the effort or cost to bore out a 5.3 and try to use old LS1 pistons. I'd rather keep a 5.3 bone stock and use an eBay chinese turbo before I went to all the trouble of an extra .4 liters of displacement.

Cam the 5.3, buy hptuners, learn to tune yourself, and have at it. Focus on the torque curve when selecting a cam and you'll have a blast for sure.

 

I saw the thread on tech.My opinion is spend the money elsewhere.I dont think its worth the money to punch it out unless your going for a more max effort build.If you are doing it just to say I got a iron 5.7 to be unique..its only going to impress a small crowd.I can tell you when people see under my hood..they cant tell if is a 4.8/5.3/5.7 etc unless they know where to look..and at that point..all they care is that its an ls something or other lol.

You can take the extra money you would spend on the rotating assy./machining and put it towards a proper matched heads cam combo.Paired with an ls6 intake and longtubes will wake that motor right up.

There are many *** kicking heads cam 5.3s out there on cheap budgets,many guys who blew up ls1's..picking up used 5.3s and making good power.If you want to make something of it without going crazy..5.3s on the bottle run Hard!

 

Pushrods, valvesprings, injectors, and a 76 mm turbo. Problem solved.

 

If you dont wanna go turbo (which I would).

I say toss on a milled down set of LS6 heads, dual springs, a decent cam and a LS6 intake. Then set of 1 7/8 long tubes. That combo in a third gen should touch 11.90's on a tire.

My buddy has a 5.3 Swapped 94 T/A and ran 12.40s heads/cam/exhaust. It may have went quicker with another guy driving also. (T56 car) 4th gens are A LOT heavier also.


If boosting it, Keep the motor stock with some ARP hardware, truck manifolds flipped and a 70-78mm and let it eat.

Jay

 

Less worrying, more turboing.

 

Im going to install a set of flat top pistons and keep it 96mm. My question is, would a set of milled down LS6 heads be a good investment? And what size cam would pick up a good amount of power? I'm going to add the bottle for sure, 150hp shot wet kit. This is just me thinking but my thoughts are a set of 243's, don't know how much to mill them though, and a Torquer V2 cam from Texas Speed. I'd like to put down around 350+ to the tires on motor alone.

 

350 RWHP with a flat top 5.3 with 243s, torquerV2, ls6 intake, with nice exhaust and CAI is realistic with a good rear end gear. I have a set of 243s on my car that have been milled .025, without any intake alignment issue, although I think .030 is generally considered max without having the intake machined to keep good alignment with the heads.