head dilemma..port 853's or buy 243's
04-23-2009, 04:52 PM
#22
Stock unmodified 243s really are a tremendous value. I've seen virgin untouched 243 heads make an easy 25rwhp over stock 853s and 241s day in and day out. Add a good valve job and some milling and you're looking at close to a 40rwhp gain. Something to consider when on a budget.
04-24-2009, 06:42 AM
#23
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04-24-2009, 10:19 AM
#24
With the PRC heads & the valve heights setup in the configuration we use you'll be able to mill well over .020" & still maintain good p/v with the camshaft in your sig.
Typically we'll see ATLEAST 20rwhp over the stock LS6 head. Considering LS6 heads probably cost $500, spring kit cost $275, Milling Cost $75. Your going to be really close to the cost of a good cnc ported PRC LS6 head.
For the last few dollars you get a cnc ported head instead of a out of the box head with a spring kit installed....
Typically we'll see ATLEAST 20rwhp over the stock LS6 head. Considering LS6 heads probably cost $500, spring kit cost $275, Milling Cost $75. Your going to be really close to the cost of a good cnc ported PRC LS6 head.
For the last few dollars you get a cnc ported head instead of a out of the box head with a spring kit installed....
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Jason
Co-Owner, Texas Speed & Performance, Ltd.
2005 Twin Turbo C6
404cid Stroker, 67mm Twins
994rwhp/902lb ft @ 22 psi (mustang dyno) www.Texas-Speed.com
Jason
Co-Owner, Texas Speed & Performance, Ltd.
2005 Twin Turbo C6
404cid Stroker, 67mm Twins
994rwhp/902lb ft @ 22 psi (mustang dyno) www.Texas-Speed.com
04-24-2009, 12:09 PM
#26
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With the PRC heads & the valve heights setup in the configuration we use you'll be able to mill well over .020" & still maintain good p/v with the camshaft in your sig.
Typically we'll see ATLEAST 20rwhp over the stock LS6 head. Considering LS6 heads probably cost $500, spring kit cost $275, Milling Cost $75. Your going to be really close to the cost of a good cnc ported PRC LS6 head.
For the last few dollars you get a cnc ported head instead of a out of the box head with a spring kit installed....
Typically we'll see ATLEAST 20rwhp over the stock LS6 head. Considering LS6 heads probably cost $500, spring kit cost $275, Milling Cost $75. Your going to be really close to the cost of a good cnc ported PRC LS6 head.
For the last few dollars you get a cnc ported head instead of a out of the box head with a spring kit installed....
Your Price: (customized)
$1,274.99
Do you have any third party dyno tests done of your heads versus stock 243 heads?
04-24-2009, 07:39 PM
#31
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Be leary of volume being pushed on you OP. Stick with whats been rec'd already. Stock 243s for what you are looking for. They really do well with a person who knows what valve job and back cuts to make to get them to shine as good as others CNC heads.
04-27-2009, 03:54 PM
#32
so i bought a set of 243's....now would you guys recommend getting them milled and running a stock gasket or just running a smaller cometic gasket? and what size gasket/how much will i need to mill to reach the ballpark of 62cc? thanks!!
04-27-2009, 04:04 PM
#33
also where is a place i can get some header bolts? one of mine is broke...
and so far for my list of parts for the head swap is as follows
-pushrod length checker (just to see)
-LS7 lifters
-cometic or stock headgaskets?
-GM head bolts
-oil/coolant
-header bolts/studs
anything else?
and so far for my list of parts for the head swap is as follows
-pushrod length checker (just to see)
-LS7 lifters
-cometic or stock headgaskets?
-GM head bolts
-oil/coolant
-header bolts/studs
anything else?
04-28-2009, 02:02 AM
#34
You will need .015"-.020" removed. I had .020" removed on mine and they came out to 62cc's, but I also did a valve job which sunk the valves down a littler further. It cost me $50 to have the heads milled and $28 for GM MLS .051" gaskets from scoggin dickey. You still come out cheaper than the cometic gaskets and the gm gaskets are great. I ended up right at 11:1 compression. For a header bolt go to fasteners or a hardware store and match up a bolt, make sure you get stainless or it will rust.
My stock 243's were 64.5cc's and it takes around .0065" to take off one CC. I have a much much smaller cam than you and my PTV clearance was close, so you will want to check it for sure and make sure your cam is degreed properly.
My stock 243's were 64.5cc's and it takes around .0065" to take off one CC. I have a much much smaller cam than you and my PTV clearance was close, so you will want to check it for sure and make sure your cam is degreed properly.
04-30-2009, 02:39 PM
#36
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Good choice on getting the set of 243's. I gained 35 rwhp & 25 rwtq by swapping from 853's to 243's (both untouched), and a new tune of course. Be sure to let us know the results.
