Omega Doom

iTrader: (2)

will they fit a stock block LS1?

ChevyChad

iTrader: (50)

yes... but the LS1 intake manifold wont fit the heads...

Omega Doom

iTrader: (2)

what about the LS6 intake?

ChevyChad

iTrader: (50)

nope...

Brad Hutchcraft

iTrader: (8)

you would need an L76 intake.

A_VAS

iTrader: (16)

I wondered this myself...I saw a set on Ebay recently...asked the guy and he said they were 243 castings, but didn't know the chamber cc or valve sizes.

If they are 243's are they using this casting and changing the intake bolt pattern?

Order 66

The LS3 head will fit a LS1 block. But the LS3 is made for a 4.06 bore and the LS1 bore is 3.9. its a little to big.

fenix999

iTrader: (17)

exactly, but just because its made for soemthing else doenst mean it wont work, and work well it does. You just need the right intake with the right rockers (exhaust i believe) and if you keep the L76 injectors you have to get an adaptor harness from speartech to you those "newer" style injector with your "older" style LS1 injector harness. The "newer" LS2 and up injectors are shorter and have a different plug as well. Hope this helps

5.3LJimmy

iTrader: (10)

They won't work on a 3.9" bore b/c of the 2.16" intake valve. They require a minimum 4" bore.

RGKSR

iTrader: (9)

I thought the LS3 head was the same casting as the L92 head. If that's the case then they will not fit on a LS1.

Bob K.

LS1W66

Yes LS3 and L92's are the same castings so they won't work on an LS1/LS6