706 heads on '01 LS1

**blackhawk01** · 12-01-2008, 12:28 PM

Just wondering if anyone has played around with this before...I have access to some 5.3 heads (706) and was wondering how how these would do on the LS1 and what type of gains I could see with these

**mark21742** · 12-01-2008, 05:31 PM

I know a few guys running them. ported and bigger set of valve and you have a good set of heads(about $500 in parts and machine shop labor) yhats not bad

**big hammer** · 12-04-2008, 05:55 AM

what's the advantage with the 5.3l heads over the stock ls1 heads?

**mark21742** · 12-04-2008, 07:14 AM

Originally Posted by big hammer

what's the advantage with the 5.3l heads over the stock ls1 heads?

smaller chamber gives you a slight bump in compression, but you can get power out of any heads with a good port n polish

**blackhawk01** · 12-04-2008, 10:12 PM

would it be worth the 250 bucks for a NICE set i can get from a u pull it?..they are on the engine

**mark21742** · 12-04-2008, 11:31 PM

Originally Posted by blackhawk01

would it be worth the 250 bucks for a NICE set i can get from a u pull it?..they are on the engine

I'd say yes, but look around 1st, you might be able to find a set for cheaper....$250 for the heads + $500 for machine shop and parts you would still have a nice set for a really good price, and I've seen 500hp+ with these heads.
probably the way I'm going to go too

**KING Z28 HAWK** · 12-08-2008, 10:03 PM

what can you get a set of these heads from?

**mark21742** · 12-08-2008, 11:24 PM

Originally Posted by KING Z28 HAWK

what can you get a set of these heads from?

( I think) any newer pickup with the 5.3l. on the passengerside head look at the front corner for the casting numbers 706

**blackhawk01** · 12-09-2008, 11:46 AM

yes..and I believe all of the 07's and up all came with the 5.3L HO which was equipped with the 243 heads

**0rion** · 12-09-2008, 12:09 PM

don't get the 5.3's unless you plan on putting larger valves in there. The stock 5.3 heads have smaller valves. I personally wouldn't do the work unless they were ported/polished with larger valves.

**Ohioc5** · 12-10-2008, 02:43 PM

My 5.3 heads just came today, they have the bigger valves and are 60cc's I paid 1200.00 for the pair, new castings, dual springs, Ti retainers and ported/polished. I'll let you know how they perform.

**0rion** · 12-10-2008, 05:28 PM

I currently have PRC 5.3 heads stage 2.5 with a 228R cam. Good street set up.

**mark21742** · 12-10-2008, 05:41 PM

Originally Posted by 0rion

I currently have PRC 5.3 heads stage 2.5 with a 228R cam. Good street set up.

in your opinion, 24 3heads or 5.3?
I would be doing the port & polish myself.
I have a friend that can put the bigger valves in for a little bit of nothing if I go with the 5.3s, all I would have to do is buy the valves

**blackhawk01** · 12-11-2008, 10:32 AM

Originally Posted by Ohioc5

My 5.3 heads just came today, they have the bigger valves and are 60cc's I paid 1200.00 for the pair, new castings, dual springs, Ti retainers and ported/polished. I'll let you know how they perform.

let me know how that works out for you man..im in an A4 so hopefully heads will benefit me just as good as if I were to have an M6

**side2000** · 12-11-2008, 12:18 PM

Originally Posted by mark21742

in your opinion, 24 3heads or 5.3?
I would be doing the port & polish myself.
I have a friend that can put the bigger valves in for a little bit of nothing if I go with the 5.3s, all I would have to do is buy the valves

if you already have the 243's then by no means get the 5.3's. mill the decks and stick some valves in the 243's. . . .getting the decks milled .030 will yield the same comp ratio of the 5.3 heads unmodified (10.9:1). millin' costs about 150 for a set (at least the shops ive dealt with) so if perhaps you could pick up a free set of 5.3's or you already have them, doin the work on the 243s would save you money.

-oh and i've put 2.02/1.6 valves in stock 243 bowls numerous times w/ no problems. some say they won't do it, some do. if you go bigger than that then bowl work must be done.

**mark21742** · 12-11-2008, 05:14 PM

Originally Posted by side2000

if you already have the 243's then by no means get the 5.3's. mill the decks and stick some valves in the 243's. . . .getting the decks milled .030 will yield the same comp ratio of the 5.3 heads unmodified (10.9:1). millin' costs about 150 for a set (at least the shops ive dealt with) so if perhaps you could pick up a free set of 5.3's or you already have them, doin the work on the 243s would save you money.

-oh and i've put 2.02/1.6 valves in stock 243 bowls numerous times w/ no problems. some say they won't do it, some do. if you go bigger than that then bowl work must be done.

all I have at the moment is my 241s

lots of salvage yards around here so I know I could pickup a good used set of 5.3 heads for real cheap and get my friend to big valve it for me

**Ohioc5** · 12-12-2008, 04:18 AM

Originally Posted by blackhawk01

let me know how that works out for you man..im in an A4 so hopefully heads will benefit me just as good as if I were to have an M6

No problem, I ran a 12.30 at 112 mph 1.90 60' with cam and bolt on's. So, I hoping with heads I can dip into the 11's. Heres a little video of my car at idle.

My wife is no videographer

http://s5.photobucket.com/albums/y17...urrent=011.flv

Heres a couple of shitty track videos. 1st one killen a SC Mustang.

http://s5.photobucket.com/albums/y17...ustangkill.flv

Second, who cares it was an s-10 but the video is a tad better.

http://s5.photobucket.com/albums/y17...rrent=1238.flv