Parks336

01CamaroSSTx

iTrader: (3)

The 4.8/5.3 blocks share the same cathedral style heads as the LS1, LS2 and LS6 all being the Generation III family of LS engines. You can use and iron 4.8/5.3 block and bore/hone to an LS1 5.7 bore and have an iron LS1. Go a step further with a good forged stroker crank, rods and pistons and achieve 383ci. The LS2 and LS6 share the larger 4.00" bores.

Parks336

I appreciate the info. I had kind of came up with that idea just didn’t know for sure. So it would be a lot let work just buying a 5.7 from the start I am presuming.

01CamaroSSTx

iTrader: (3)

Yes but the most you can go on the 4.8/5.3 or the 5.7 aluminum blocks is a 383. It would really depend on your budget and what your looking to do. Some people are turbo charging those small bore engines and making a ton of power.

Parks336

Gotcha. Makes sense the 5.3 are readily available .

01CamaroSSTx

iTrader: (3)

I'd roll the dice on the 5.3 iron over a 5.7 aluminum block any day.

Parks336

I don’t know much about EFI . Would it be easier for the conversion to carburetor kit and running a carburetor?

R6cowboy

iTrader: (3)

Couple corrections here to help out the OP. LS2 does have cathedral heads from factory but they're generation 4 engines, not gen 3 like the LS1/LS6. There are both gen 3 and gen 4 4.8L and 5.3L engines, gotta watch for engine codes. Also, the LS6 does not share the 4.00" bore like the LS2, it has the same 3.89" bore as the LS1.

Another thing OP, iron LS blocks (regardless of cubic inches) are almost right at 100 lbs more weight than aluminum LS blocks. That's a lot of weight to overcome when talking performance. If you're not going to exceed around 1,000+ hp, try to stick with an aluminum block if it's within budget. Aluminum LS blocks are still very strong and can withstand a lot of power, 800-900hp is perfectly fine for a nicely built aluminum LS block and can last quite some time is taken care of.

R6cowboy

iTrader: (3)

Do some homework and you'll find out the LS EFI isn't all that difficult. Custom tuning takes some time and experience of course. EFI is definitely the way to go, usually. Especially if its a street car/cruiser and mpg & street manners are a concern. Take my old C5 corvette for example which was a 100% street car/cruiser. It was a ~500hp (430whp), stock bottom-end LS1 with ported factory heads and mild-medium sized 227/230 duration cam, among other typical bolt-ons and supporting mods for heads/cam setup. It had the manual 6 speed trans, drove very smooth, excellent street manners and literally got 30-32mpg on the highway.

01CamaroSSTx

iTrader: (3)

I was referring to the LQ block or the 6.0 iron block. I have a 2003 Silverado with the LQ block and have always called it an LS6 but I guess that's not the case.

To the thread starter here, try locating the book How to Build and Modify GM LS-Series Engines by Joseph Potak. That book has a lot of information on choosing the right block and building LS engines.

ss.slp.ls1

iTrader: (36)

^^^Great book.

Parks336

I’m thinking close to 500hp is where I want to be. Possibly a turbo, cam, etc.

R6cowboy

iTrader: (3)

Don't fall for the "you want an iron block for turbo" myth. If it's in the budget or you find a good deal, get an aluminum block, 500-600hp is no where near the limits of one. Its just a lot of weight savings. Also both aluminum and iron 5.3L engines can be bored to 3.910", which is 347 cubes. Just a little FYI.

01CamaroSSTx

iTrader: (3)

The LSX block is capable of over 2,000 hp and is designed for use of six bolt cylinder heads, more clamping force for those boosted applications which was why I went with an LSX block. Gives me something to build on later down the road. That is if my pockets ever get deep enough to let me...

01CamaroSSTx

iTrader: (3)

I've heard it makes more power than EFI but with today's advancements with EFI carburetors I don't know if that's entirely true.

Parks336

You answered my next question. I have seen that quite a bit through all the reading .

R6cowboy

iTrader: (3)

For your plans power wise, you could fill a 5.3 aluminum block with forged internals, bore it 3.9" to 5.7 liters if you wish (boring would really help unshroud the use of 2.00" or 2.02" intake valves), and have a nice bottom-end foundation for a long time.