Turbo_TA_Jay

Im starting a 5.3 turbo build

I keep seeing different people emphasizing the 8th vin letter. I dont know what the differences are besides i believe they show the gen of the motor but whats better or what should i stay away from?
Plan on using a Huron Speed V2 kit, and cam, trying to reach 700ish rwhp

NoorJ

I think any variation 5.3 would be fine for 700whp. The 05+ 5.3 has the stronger LS2 rods, that would be vin "T" if you want the iron block.

Turbo_TA_Jay

If i run a custom grind cam to spec match the turbo kit do you think the ls2 rods would be enough or would it be recommended to upgrade? From what ive read guys are just grabbing a 5.3 and slapping a turbo on it tuning it and pulling crazy numbers without touching a thing but im a skeptic lol

67Firebird455

iTrader: (27)

It's still all in the tune! I'd leave the bottom end alone, cam/pushrod/spring swap, trunion upgrade kit for the rockers and call it a day with some LS9 head gaskets and ebay head studs.

Turbo_TA_Jay

So even factory 5.3 heads should be fine, just change gaskets rods springs and upgrade the rockers... hmm sounds alot easier then i was planning

67Firebird455

iTrader: (27)

There are plenty of guys making big power with factory 5.3 heads. Many opt for 243's or 317's, but if you're on a budget, or not building an all-out 5.3 setup, stick with factory heads.

Forcefed86

iTrader: (4)

I'd strictly look for 2005+ and leave the factory internals alone. Alum blocks are about 80lbs lighter and plenty strong for 700whp. The alum block 5.3's also come with the "good" 243 heads. They would be the ideal 5.3 to run for your goals IMO. The older gen3 L33 engines are alum too. They also have the better pistons/rods if you can find one.

The more power you make NA, the more power per lb of boost you'll make. Figure out a boost level your comfortable with, then build the motor appropriately. If you want 700hp at 15lbs you'll need to make roughly 350hp NA. If you have the octane to run more boost you can get by with less power NA.

According to the weight trap calculators I'm making 700+ at the wheels with a tiny cam (212/212 @ 112) and ls6 intake on a stock 4.8 long block (small heads) at 19-20lbs of boost, S476 turbo. Running E85 for fuel.

JoeNova

Any 5.3 will work. Even the older ones have been pushed to 700whp on stock internals.

I'd grab a 5.3, put on ls9 Headgaskets and ebay studs, and mild cam and spring combo, and cram boost down it's throat. The stronger floating rods are a bonus.

Sarg

iTrader: (6)

Liljohn on here also has mls gaskets specific for the 5.3 bore which would work well. If they had them when I slapped my motor together that is what I would have purchased over the ls9 gaskets.

Forcefed86

iTrader: (4)

Alot has to do with weight, tune, luck, etc... Many have also bent rods well under 700hp on the gen3 stuff. I'd skip the gen3 stuff personally. I've still never paid more than $600 for a gen4 5.3/4.8.

Felpro has the small bore head gaskets in their MLS permatorque line too. Same gasket the guys running 4's at 40lbs of boost on SBE 5.3's.

RonSSNova

iTrader: (3)

I'm running that Felpro thanks to Forcefed's suggestion. Solved my issues. I think it's better for an alum block 5.3.

2muchboostNY

iTrader: (8)

Aluminum will do most just go iron block cause of price and availability. S13lsx went into the high 8s with a stock block in a 240sx chassis as reference. Stock heads will do but if you can get the 243 heads on the aluminum block that's ideal.

I have an 05 LM7 iron block which has the upgraded rods but kept the 24x reluctor wheel. Guess it's the hybrid year between Gen 3 and Gen 4?

Photochop

iTrader: (74)

Just buy a 2005 L33 5.3 for the reasons forcefed said. It's kinda silly not to, for me it was $150 more than a 2005 iron block. The lighter weight and better heads on the L33 make it more than worth the cost difference.

Turbo_TA_Jay

Ok so sorry for digging up my old thread but I had to put the Trans am on hold for a bit. But its time! Bout to buy an engine. Looking at either an L33 or LM7
I know the 33 is aluminum and the M7 is Iron
The aluminum is 80 lbs lighter which is nice but not huge
From what i understand the 33 will be fine to 700 hp no problem but will i have issues if i try to push it to say 1000? and im just talking block. if i went that high i will have done some internal work where for now around 700 i dont intend to.
Should i go straight for iron just to know later if i want more power im safer?
Need options and need a motor!
Please Help! Thanks

Sarg

iTrader: (6)

One of the fastest stock short block cars to date was Skinnie's car with a L33 that was pushing over 900 at the wheels if I remember right.

93NotchLX

iTrader: (1)

I'd look for a 2007+ 5.3 with flat tops. Or an L33 if you need to stay 24x.

Stuffs

can you share part number?

RonSSNova

iTrader: (3)

I looked them up for you.

26190PT for the L33 vin B
26191PT for the iron 5.3

I don't think they had a specific part for the alum engine when I bought mine. Must be new!

Ron

Forcefed86

iTrader: (4)

According to the felpro support chat it looks like the only difference is bore size... ? Don't know why you'd want the larger bore gasket on the L33?

http://www.felpro-only.com/break_roo...id=313&pid=899

tblentrprz

If memory serves me well, the L33 is topped with the larger bore 799 head hence the larger bore 26190PT gasket (same spec'd for ls1)