Look for a post in the Dyno section where I installed a set of Bo's 5.3's on Jlaw's car with a F13 cam. They turned out pretty good and he used a set of PRC duals on them.

 

The PRC, PP, Comp spring kits fit all of the LS style engines. The link to JLaws post:
www.ls1tech.com/forums/showthread.php?t=286127
His heads were the first set I done with the newer intake port I am doing and flow #s will be posted as soon as I get em.

 

Those look great Bo, and the numbers in that post are very nice as well. Sent you a PM, trying to find me some heads for you to do some work on as we speak.

 

So, I should go with 5.3 heads? With your work on the 241's, I'm guessing the comp drops some. Same price to do 5.3's?

 

When I deshroud and polish the combustion chambers on any of the LS style heads I remove about 3cc of material so I then mill the heads .018" or so to get the compression back were it was at. Its the same price for doin up a set of heads no matter the LS style head(5.3,5.7,6.0).

 

What would you say the power difference would be? I like the idea of using my existing heads and the "stealth" factor.

 

The main thing you gain goin 5.3s is the compression increase which is usually 10 more at the wheels over the 5.7s.

 

You are the man. Thanks for the quick replies. Time to find some 5.3's.

 

Couldn't you just have the 5.7's milled later to get the same gain as the 5.3's? Reason I ask is that I have a spare set of 241 heads in my garage that I may send off to you when I finish my rearend buildup.

 

You can, you will just have to mill them an additional .036".

 

Bo, I sent you an email, but I misread your post...

So if I sent you bare heads to be ported with no assembly, and you ported them and sent them back, that is $450. The assembly and machining is where the extra $200 comes in? Does that $450 include milling the heads?

I'm looking at that $450 price and all I need is port work and milling to get the 5.7L heads up to 5.3L compression. Can that be done for $450? If so, I'm picking up a set of heads next weekend and will get them on the way to you shortly thereafter.

 

I PMed ya. Correct, if someone sends me a set of bare heads to be just ported and shipped back it will be $450. Then they will take care of the machining and assembly on their end. The $650 price is me handling the machining and assembly too.

 

Let me say that while I haven't gotten anything back from Bo yet (throttle body should be in his hands this afternoon via UPS, heads wont be going out to him for a few more weeks), his communication has been excellent. I'm emailing him a few times a day it seems asking this or that, and he always gets back to me fast and with exactly what I need to know. So far I'm having a very positive experience, and from other people, I definitely think I'm in good hands here.

Looks like I'm going to get some 853 castings ported and milled for 11:1 compression (static). I was going to have to take them somewhere else to have them milled but Bo is going to handle that for me for a good price, so it's all set. I just have to get these heads from my friend and ship them out to Bo. It'll be a while before I have everything together and on the car, and that works great with Bo's time table, but when the time comes, I'll be sure to post with pictures, dyno numbers, and time slips.

Thanks again for all the help Bo. I love this forum.

 

The 5.3's must offer something other than a compression bump or everyone would just mill their 5.7's right? Flow velocity differences?

 

When you start milling heads, you limit yourself in cam selection due to the loss of P/V clearance. Also, milling heads screws with the valvetrain geometry on our non adjustable valvetrains.

 

Yes, when ya mill the heads .050" that makes the valves .050" closer to the pistons than they were before and when ya mill the heads .050" you have to run .050" shorter pushrods than before. Also, when milling large amounts the intake alignment becomes an issue.

 

All good to know. Bo, sent you a PM and email. Looks like I'm going for the full $650 job w/ extra milling to get close to 5.3L compression. I'm running a smaller cam (221/221 .558/.558 112 LSA), the extra milling isn't going to cause an issue with PVC is it? And I'll need to get pushrods of what length? Thanks for all the help and any more.

 

lookin good Bo!!

 

It will be close, whats the ICL?


Thanx cyphur

 

Ok. Duh. Thanks, looks like 5.3's are for me, I couldn't stand the idea of 10rwhp less for whatever some 5.3 heads would cost me.