I might be buying some heads....

Reply Subscribe

Thread Tools

Search this Thread

Mar 16, 2004 | 04:38 PM

soundengineer

Thread Starter

8 Second Club

iTrader: (16)

Joined: Jul 2003

Posts: 4,651

Likes: 17

From: Chicago IL

I might be buying some heads....

are these the right ones to buy for an ls1???
getting them from a friend....set has been ported and polished...valves included.
I'm getting them with no springs or retainers....but I alredy have those....

I have a 2000 ls1

Mar 16, 2004 | 08:27 PM

blk~2000~Z28

TECH Resident

Joined: Jul 2003

Posts: 834

Likes: 0

From: Marysville, OH

Here is a list of a few casting #'s:
853 97-00 aluminum 5.7
241 01-03 aluminum 5.7
243 LS6 aluminum 5.7
852 and 706 99 and up 4.8-5.3 truck heads
873 99-00 LQ4 6.0 iron heads
317 01 and up LQ4 6.0 aluminum heads
035 02 and up LQ9 6.0 aluminum heads

Mar 16, 2004 | 09:02 PM

v8pwr

TECH Enthusiast

iTrader: (19)

Joined: Dec 2003

Posts: 538

Likes: 2

From: florida

706 Heads

As The List Above Mentioned You Have The 5.3 Heads.stock They Have The Same Intake And Exhaust Port As An Ls1 Head They Just Have A 1.89" Intake Valve Whereas The Ls1 Has A 2.00.these Heads Are Used To Bump Up The Compression Without Milling.i Have The 862 Casting.

Mar 17, 2004 | 12:23 AM

soundengineer

Thread Starter

8 Second Club

iTrader: (16)

Joined: Jul 2003

Posts: 4,651

Likes: 17

From: Chicago IL

So I should be ok with just slapping them on If I buy them???
what kind of compression ratio should I expect?
and will the smaller intake valve hurt me any??? or should I make sure there is a 2.00 intake valve in it??

Mar 17, 2004 | 12:28 AM

blk~2000~Z28

TECH Resident

Joined: Jul 2003

Posts: 834

Likes: 0

From: Marysville, OH

Quote:

Originally Posted by soundengineer

The smaller intake valve will definently not help, it is a toss up between how much it will hurt you vs. how much benefit you will gain from the compression bump. Most would choose to stick with stock 5.7's and mill to have the bigger valves and a compression bump. The downside is resizing your pushrods and piston to valve clearance issues. The compression depends on how much the heads have been touched in the CC. If there has been material removed then it will be a little less.

Mar 17, 2004 | 01:57 AM

soundengineer

Thread Starter

8 Second Club

iTrader: (16)

Joined: Jul 2003

Posts: 4,651

Likes: 17

From: Chicago IL

so will I need a different length pushrod with these heads???
and will I have PtV clearance issues with my X1 cam??
and If it has the smaller valves in it...should I take it to a local machine shop, have them make it fit a 2.0 valve...and buy some valves to fit??

Mar 17, 2004 | 02:44 AM

blk~2000~Z28

TECH Resident

Joined: Jul 2003

Posts: 834

Likes: 0

From: Marysville, OH

Quote:

Originally Posted by soundengineer

If you are getting a killer deal on these heads it may be worth the trouble. The problem is "Are these heads even worth the effort?" Who ported them? Do you have any idea of what they flow? Would it be cheaper to get a set of Stage II 5.7 or 5.3's from a sponsor that have a warranty and come with a flow sheet. Given that you have a X1 cam you should have decent heads to compliment it, not something that is a little better than stock.

If the heads are unmilled then there should be no issue with PtV clearance.

Reply Subscribe