98_WS6_M6

iTrader: (18)

What would the difference be in using the LS1 5.7L heads vs. the 5.3L heads? I heard the 5.3L flow better but there has to be a downfall to using them. I am going with the TR230 cam and maybe some juice in the future.

camaro99SSdvl

yeha i got a post just like yours under ya, I've heard that they flow better than LS1 heads as well, im curiosu myself

Jimmyz

iTrader: (3)

The 4.8 & 5.3's offer no advantage over the LS1 head except for a smaller combustion chamber. If you mill the deck surface, it will let you achieve a slightly higher compression ratio. This is straight out of the May 2003 GMHTP Mag.

Ron@Vengeance

iTrader: (51)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Jimmyz:
<strong> The 4.8 & 5.3's offer no advantage over the LS1 head except for a smaller combustion chamber. If you mill the deck surface, it will let you achieve a slightly higher compression ratio. This is straight out of the May 2003 GMHTP Mag. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Quit reading magazines and go build a damn motor <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

Jimmyz

iTrader: (3)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Cammin BeaSSt:
<strong> Quit reading magazines and go build a damn motor <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">That's really funny...I couldn't build a model airplane. <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

98_WS6_M6

iTrader: (18)

So what's the sacrifice you make by increasing compression? If I am using 230/224 .575/.563 111 LSA cam and planning on maybe sprayin' in the future, a TNT 100 Wet Shot. I heard that with my setup I may smack a valve. <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />

XLR8VRL

The 5.3L heads have the same port volumes
the 5.3 has the same exhaust valve size but a smaller intake valve , however the seat is the same and can be machined to accept the 2.00" 5.7L intake valve the chambers are slightly smaller so you will see an increase in compression WITHOUT milling the head which might help you with V/P clearance good luck i have a set on the bench getting ready to go on soon I saw a buildup with a mild port job on these heads, a cam,bigger MAF and TB, long tubes, and LS1Edit programing - was putting down 500Hp at the wheels awesome <img border="0" alt="[burn out]" title="" src="graemlins/gr_burnout.gif" />

98_WS6_M6

iTrader: (18)

So should I go with 5.3 or 5.7 heads for my setup?

XLR8VRL

compression = power! I`m gonna go with the 5.3L`s
you shouldnt have V/P clearance probs if you dont mill the heads too much.
PS; my old small block stroker is 12 to 1 comp never had any probs but it doesnt like pump gas - I mix 110 sunoco with 93 amoco half and half and it loves it <img border="0" alt="[burn out]" title="" src="graemlins/gr_burnout.gif" />

98_WS6_M6

iTrader: (18)

If I go with TEA's Stage II 5.3L heads would I have any problems? What would be the gains over TEA's Stage II 5.7L heads? If spray was added to the equation later what effect would the different size heads have on that?

TEA Brent

The 5.3 head does flow better (asuming your talking ported) on the intake and exhaust. The 5.3 head builds compression without milling at all. This leaves you with a much larger piston to valve clearance. The 5.3 head flows 15cfm better than a 5.7 so it is a killer nitrous head. I hope I answered everything for ya, if not let me know.

GeorgeC

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by XLR8VRL:
<strong> I saw a buildup with a mild port job on these heads, a cam,bigger MAF and TB, long tubes, and LS1Edit programing - was putting down 500Hp at the wheels awesome <img border="0" alt="[burn out]" title="" src="graemlins/gr_burnout.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Where did you see that? Most of the big 420+ cid motors seem to only make a little over 500rwhp. I haven't had my ARE 382cid solid roller on a dyno, but it should be in the ~500rwhp range.

I think you saw/read something incorrectly. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

98_WS6_M6

iTrader: (18)

So are there any downfalls at all to going with the ported 5.3L heads?

I heard that you were running the GeorgeC , what do you recommmend?

98_WS6_M6

iTrader: (18)

Thanks guys, these are the answers I've been looking to get for about 2 weeks now.

What if I sprayed with the TR230 cam I mentioned above and the 5.3L Stage 1.5?

Vince : I plan on using QTP's LT 1 3/4" Stainless Steel Race Style Headers, QTP's off-road y-pipe, to a Hooker Cat-back. Running dumps at the track. Do you think this will flow well enough?

VINCE

iTrader: (1)

I am obviously no exhaust expert.. I am still running Macs.. I think you will do well with the setup mentioned.. Make sure you get the proper merge collectors. You want some scavenging..

Mike K.

I know it was a fluke but after seeing what Vince went through with his 5.3 heads I am scared to use them although most people do get more power with them.

98_WS6_M6

iTrader: (18)

What happened to Vince?

98_WS6_M6

iTrader: (18)

Are there any downfalls to having too much flow on the exhaust side? I'm comparing TEA's Stage II to Stage 1.5, 5.3L heads. The 1.5's flow 15cfm more on the exhaust because they use the stock valve instead of aftermarket valve.

VINCE

iTrader: (1)

I see no down falls with running the 5.3L head. Just be aware that milling them will increase compression and that will require a better tune to prevent detonation on pump gas.. A good tuner can give you killer #'s with these heads.. If I were to stay NA I would swap my heads for some 5.3L's and run higher compression. I also have valve reliefs, so milling them .050 would be fine for me even with my 232 cam.. Matching the exhaust is also important when building a setup.. You can have a killer H/C setup, but if your exhaust is your bottleneck you will never see your cars true potential..

GeorgeC

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by 98_WS6_M6:
<strong> So are there any downfalls at all to going with the ported 5.3L heads?

I heard that you were running the GeorgeC , what do you recommmend? </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I'm not an expert, but I do like the 5.3 heads. I used them on my current motor since the flow numbers are just as good as an LS1 head, and the smaller combustion chambers helped get the compression ratio we wanted (which is pretty high) w/o too many piston to valve clearance issues with the huge cam I'm running.