fastbird02

iTrader: (4)

here is my question, i have searched a little and all i hear is that no, but no reason why. here is my question

ls1 and ls2 use the same heads. with an intake and heads you can convert a ls2 to a ls3. (drum roll please) why cant you bolt that same intake and heads to a ls1??

sorry if im an idiot, or if I didnt search enough... but its really bugging me...

-Bruce

DREAMZ28

iTrader: (1)

I think it's bore size shrouding the valves.

fubar569

iTrader: (9)

basically.

LS1 is what...3.89" bore or somewhere in there

LS2 is 4.0" bore

LS3 is a bit bigger yet...

The only reason small bore "LS3" heads exist is people replace the larger OEM valves with smaller ones to fit the smaller bore of the LS1 block.

The minimum recommended bore size for "LS3" style heads is 4.00

fubar569

iTrader: (9)

Correct. They do have "small bore LS3" heads...but they DO have smaller valves as i stated...for the reasons i stated...

There's nothing wrong with going that route and they will perform just fine...but you're literally taking a head designed for X application, handicapping it and taking a step back...just to use it on Y block...

Considering the results obtainable for the same or less money using existing parts...is it really worth it?

JakeFusion

iTrader: (7)

Yup. The bore of an LS3 is 4.065" and LS2 is 4.000" and LS1 is 3.898"... the LS3 heads don't perform as well on an LS2 as the LS3 due to valve shrouding and they won't fit on an LS1 due to the size of the valves.

As stated, there are small bore applications for the LS1. MAST and a few other companies offer small-bore LS3 heads with 2.08" intake valves vs the 2.165" stock LS3 valve. They use the same LS3 offset rockers and LS3 intake manifold. But the runners are very big... 240+cc which may be a little much for a 346... but perhaps not for a 383 or 395 stroker application.

fastbird02

iTrader: (4)

ok, thanks you everyone.

LS1MCSS

iTrader: (18)

If the LS3 heads are stock and you sit them on the ls1 block, the exhaust valve WILL hit the top of the cylinder wall. It will not clear. This is stock LS3 heads. Not small bore heads.