Difference between VY and VZ LS1 engines

[fastrc]

I am looking at a power plant for my 1934 Hot Rod project and have access to an VY SS LS1 UTE engine with 10K klm's or an VZ SS LS1 Sedan engine with 20K klm's.

Is there any difference between the block, heads, cam etc on these two models as they are listed as producing different KW's. I know the VZ has throttle by wire but I have an 78mm FAST throttle body for either engine.

Any information would be gratefully appreciated.

[BLACKWAGON]

vz has bigger maf and pipe but i think the motors are exactly the same.
all ls1 power outputs varied from vt-vz from 225 vx 235 vys1 245 vys2.
small bits of change, maniflod, tune, exhaust, maf etc

[Tonner]

Funny that, someone here was just saying something about the rear headbolts,

[planetdavo]

Barring the electronic throttle body, any (mechanical) differences between the two are simply down to running changes from GM Powertrain. The VZ gains were pretty much PCM related, nothing else. You don't gain better flowing heads, extra comp ratio, or any good things like that.
From what you are saying about fitting a FAST, just choose the healthier engine, re compression and the usual checks, plus any price considerations of course.

[fastrc]

Thanks guys, thats the info I needed.
I'm waiting on compression readings, otherwise prices on both engines are exactly the same.

[fastrc]

I found the 09/04 VZ SS block has casting number 12561168 just under the right hand head. Does this make it an LS6 engine ?.
The VY SS engine has casting number 12551358 on the block.

Is there any advantage/dis-advantage of the LS6 over the LS1 ?.

Thanks guys, you have been a great help.

[HOWQUICK]

take the VZ.

It has stronger floating pins, bushed conrods, revised pistons, LS2 head bolt configuration and the LS6 block, valley breather which has improved breathing. It also has a better design oil pan.

Check the date at the start of the the engine number on the VY. If '04 on it is the same spec.

[beaver_roadkill]

Could you fit the vz maf and pipe on an earlier model without changing anything? Or is it spending money on an upgrade that does bugger all?

[LS1LHTORANA]

Check the heads too, plenty of people steal the 243's and put 241's in their place. The 04 motors should have the 243's.

[HOWQUICK]

Check the heads too, plenty of people steal the 243's and put 241's in their place. The 04 motors should have the 243's.

no LS1 ever came with 243 casting heads............that would make it a LS6.

[BLACKWAGON]

Could you fit the vz maf and pipe on an earlier model without changing anything? Or is it spending money on an upgrade that does bugger all?

My VY11 was fitted with the vz maf and pipe, you need an adapter cable that I think comes from Harrop.
If you are keeping maf tune then u will get some improvement bcs of more flow, just like putting the bigger YT and other aftermarket pipes on, only stock looking.
I cant give an accurate comment on the difference bcs it was done at the same time as my cam.