ok. the more i read, the less i know. i figured the 5.7/5.3 was the same as the 350/327 from back in the day, whereas the 350 and 327 shared the same block and had different strokes. i guess this is not the case as i just read the 5.7 and 5.3 have the same strokes leading me to believe that the bores have to be different. i know that the trucks have iron blocks and the ls1/6 have aluminum ones. what else is there to the equation? are the main journals the same? will a 4.0 stroker ls1 crank work in my 5.3 block? are the deck hieghts the same? what about the size of the rods? are they all 5.098" like the ls1/6? which blocks(if any) have siemesed cylinders? what else is different between the ls1s and the truck motors? ive read ls1 intakes wont swap. why? intake ports not line up or what? are the vortec heads on these engines as good for power making as the vortec heads on the 2nd gen small blocks?

this site seems awsome, im sure i will learn alot. i just got to do some research on all the sensors and **** that go along with one of these engines. does anyone know of some reading material that will help me out?

 

I cant answer alot of your serious tech questions, but i can help in one area....

The 5.3 is the 4.8 with a longer stroke. Doesnt work the same way with the 5.7 (LS1/6.

Also it is my understanding that our intake manifolds are actually better than the F-Body guys due to the fact that GM had more room to work with under our hoods then they did with the F-Bod's.

Good luck man.

 

Welcome aboard!

 

I'm not going to try and answer spcific questions, but I will let you in on what I know .. as usual .. if I need correcting, someone please set me straight!

The blocks are all the same .. for the most part. The only difference in the blocks themselves are bores. The LS1 aluminum block, all others (4.8, 5.3, and both 6.0's) are steel, has one less bolt hole on the front for what would be where our AC bracket goes. Other than this single bolt hole which isn't needed, the blocks are all interchangable.

I don't know if the big stroker cranks will fit in the blocks or not. It seems as though I may have read somewhere that the bottom needs to be cleaned out a little to make room for the larger cranks, even with the ls1.

All the gen3 engines are ls1-based. They all use the same sensors and junk too as far as I know. The pcm flash is a little different for the tables and all I think, but I'm not sure. I'm not even sure if anyone is real clear on that one.

As for the sensors .. here are some major ones:

IAT - Intake Air Temp.
ECT - Engine Coolant Temp
KR - Knock Retard, as determined by the knock sensor
MAF - Mass Air Flow
STFT/LTFT - those have more to do with the pcm than anything, but they are short/long term fuel trim

Maybe that will get you a start on things ..

 

The only reason the intakes aren't a direct swap is because the fuel system is a little different and the accessories would be in the way. It is very possible to do though with some time and money.

 

Ok lets see,

The Good old 327/350 that are based on the same small block that has been around since 1955 are the fist generation small block. Or Gen I. The early Vortec block that were in trucks from 1996 to 1999 were like a Gen I.5

The LT1 that came out in the F-body cars in 1993 were Gen II. Alot of gen I and gen II parts could be interchanged.

The motor that came in the 1997+ Corvet, 1998+ F-body, and 1999+ trucks are Gen III.

Virtually nothing from the Gen I will inerchange with the Gen III.

 

The bottom ends are the same, the 4.8/5.3 have 4 bolt mains and the 6.0/LS1(6) have 6 bolt mains also. Same cranks of 3.68" stroke (expect 4.8) and the 5.3 has a 3.78" bore, 6.0 has 4" bore, LS1(6) have 3.90" bore.

A 4" stroke crank will work but your smaller bore will not yield the same cubes of a 6.0 or LS1.

I believe the deck heights are the same through the blocks as all the pieces are interchangable. I don't think those rods are as short as 5.09"...hell that is what a 302 Ford uses and s 3" crank. I think they are around 6.1X".

Truck intake flows better than LS1 intake but the LS6 flows even better than truck. They LSX style ones will not work due to accessory locations. None of the cylinders are siamesed like days of yore on the old small Chevy or Mopar 318/360.

The newer Vortec heads are WAY better than the older iron counterparts. The iron ones are similar to the SBF GT-40P irons. Nice factory heads but better stuff is available. The new Gen III heads are great in stock form but are killer when worked over. If you need to know the differences between 4.8/5.3/6.0/5.7 heads start a new thread and I'll be happy to explain...

 

ok, according to my gm performance part manual, the rods are 5.098. i know that seems pretty small considering the old SBC rods were 5.7. you owuld figure they would lengthen them to make the rod ratio better.

also the bore/stroke for a ls1 is 3.98 and 3.62. im sure of that. a 4 inch stroke in my 5.3 would make 359 ci, about 5.9 L. putting it in between the ls1 and 6.0 in size. man if i can find a 6.0 or ls1 block i would rather do that for the extra cubes when the time comes. i might even save some cash by doing that because i dont think anyone makes pistons for a 5.3 with a 4 inch stroke, so they would have to be custom. im just working everything out in my head right now. just want to learn the basics right now. when the time comes, i will go with what ever is cheaper. maybe by then they will have 6.0 short blocks. thanks guys for all the help ive learned soo much so far.