6.0 heads

[thearborbarber]

Using 6.0 heads on a LS1 5.7 is common when running forced induction. The combo has a lower CR allowing more boost. That's the only time I've seem that combo tho.

[grampadirt]

I'm getting in over my head now,not familiar with the LS engines.I did,however,find this info on Summit's website:

 

''These Chevrolet Performance 5.7L LS1/LS6 aluminum engine blocks are direct replacements for the 2001-04 LS1 and LS6 Corvette 5.7L engines. Manufactured from 319-T5 aluminum, they use cast iron sleeves, the production oiling system, and 6-bolt main bearing caps. The Chevrolet Performance 5.7L LS1/LS6 aluminum engine blocks feature a 9.240 in. deck height and accept LS1/LS6-style cylinder heads only. The blocks feature a finished bore of 3.980 in. and do not include a provision for Active Fuel Management. Start your engine buildup with one of these Chevrolet Performance 5.7L LS1/LS6 aluminum engine blocks''

 

I didn't know they made a 5.7LS

 

So the OP's friend must have a 'Vette engine? .

[Chris]

Possible. The 6.0 LS2 also used the same 243 heads as the 5.7 LS6. But I think the L92/LS3 and 317 castings require a minimum of 4" bore

[grampadirt]

Using 6.0 heads on a LS1 5.7 is common when running forced induction. The combo has a lower CR allowing more boost. That's the only time I've seem that combo tho.

As in Corvette?

[Chris]

A few cars got the LS1/6 5.7's Corvettes, GTO's, CTS-v, Camaro

[Deadbolt]

I haven't dug into my engine as of yet. Mostly, because it a 1999 Chevrolet G1500 Express high-top conversation van. A BIG, HEAVY Bastard! You can bearly see the engine from the front and taking the Hump cover out, inside will be a pain! I'm new to Vans! But I know by the original window sticker that I have the Vortec LS L31 5.7 350. What HEADS do you think are installed on mine? Also a friend tell me it not a LS motor? Is it a LS1 or a LS2, or what? Thanks guys! Break me off, some knowledge! :-)

[thearborbarber]

You have a gen2 vortec 350. It's not of the LS series of engines. The engines have vortec heads which aren't bad flow wise for gen 1 and 2 engines. Unless you are willing to spend some big money I'd just leave it alone. They made decent power from the factory.