Stage 1 243s VS Stage 2.5 5.3 Heads
#1
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Stage 1 243s VS Stage 2.5 5.3 Heads
Hey guys,
I have a set of 243s that have been milled .030 that I have been thinking of getting ported. If i did a stage 1 port on them the would flow around 280-290. I ran across this post and now im not sure which to pick?
Stage 2.5 cncd 5.3 heads
.100" 67.2 57.5
.200" 140.4 110.7
.300" 207.8 168.7
.400" 252 212.9
.500" 291.1 240.9
.550" 303.9 248.2
.600" 317.6 252.6
Should i port my 243s or just get a set of these. The price of the 5.3s would be alittle cheaper but i want to which would be a better choice.
Thanks
I have a set of 243s that have been milled .030 that I have been thinking of getting ported. If i did a stage 1 port on them the would flow around 280-290. I ran across this post and now im not sure which to pick?
Stage 2.5 cncd 5.3 heads
.100" 67.2 57.5
.200" 140.4 110.7
.300" 207.8 168.7
.400" 252 212.9
.500" 291.1 240.9
.550" 303.9 248.2
.600" 317.6 252.6
Should i port my 243s or just get a set of these. The price of the 5.3s would be alittle cheaper but i want to which would be a better choice.
Thanks
#3
Depends on your goals and what size motor your putting these on. The only advantage to the 243s are the possibility of sodium valves but you can put those in any head and you can port the 243s more.
#6
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Sorry, I forgot to include the basics.
Its a stock LS1. When I switch out the heads im going to install a FAST90/90 and LTH/Y pipe. I wont be installing a cam for at least a couple of months.
I would like a heathy midrange because I rarely go to the track and just drive it on the weekend.
Its a stock LS1. When I switch out the heads im going to install a FAST90/90 and LTH/Y pipe. I wont be installing a cam for at least a couple of months.
I would like a heathy midrange because I rarely go to the track and just drive it on the weekend.
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1 CC = 0.006 milled off.
That's 0.030 the LS6 is already behind. Mill that off the LS6 heads and oh wait, mill the 5.3L heads and the LS6's are still behind 0.030.
In short, no, they cannot obtain the same compression ratio, and if 93 is plentiful, the more compression the better.
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#8
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If the car is used for street with cam spec'ed to be for street I would go with PRC 5.3 stg 2.5 milled to 59cc or 60cc
Those heads are well known to produce good power in the mid-range power ; with their compression will help your small / mid cam to shine everywhere
People have used these heads with 228R, 224R and TR224 with great results around 425-440 rwhp with torque that will never be below 390-410 rwtq, the car will be fun to drive with the power everywhere and that's what you need for the street
If you are building a drag car and not worry about down low or mid range and you choose a big cam, go with PRC LS6 where they shine at high RPM, people made crazy power with 243s GM cast up to 500+ rwhp
Call TSP they can advise for your heads and what gasket to achieve your CR
Those heads are well known to produce good power in the mid-range power ; with their compression will help your small / mid cam to shine everywhere
People have used these heads with 228R, 224R and TR224 with great results around 425-440 rwhp with torque that will never be below 390-410 rwtq, the car will be fun to drive with the power everywhere and that's what you need for the street
If you are building a drag car and not worry about down low or mid range and you choose a big cam, go with PRC LS6 where they shine at high RPM, people made crazy power with 243s GM cast up to 500+ rwhp
Call TSP they can advise for your heads and what gasket to achieve your CR
#9
whats your budget? how much will it cost for you to get the 243s ported?you will need a valve job and spring and seals also.you can sell the 243s if you go with the TSP 5.3 heads .
#11
Sorry, I forgot to include the basics.
Its a stock LS1. When I switch out the heads im going to install a FAST90/90 and LTH/Y pipe. I wont be installing a cam for at least a couple of months.
I would like a heathy midrange because I rarely go to the track and just drive it on the weekend.
Its a stock LS1. When I switch out the heads im going to install a FAST90/90 and LTH/Y pipe. I wont be installing a cam for at least a couple of months.
I would like a heathy midrange because I rarely go to the track and just drive it on the weekend.
Putting FASTon with no cam seems like a waste of money.
#12
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I think i might do it all at once but im still not sure. I have everything for the head/intake swap right now so that is why i thought of doing them at separate times.
I originally bought an LS6 intake but got a great deal on the FAST combo($525). The general concesus is that the 5.3s are going to be the better "bang for buck" here.
Any suggestion on a cam?
I originally bought an LS6 intake but got a great deal on the FAST combo($525). The general concesus is that the 5.3s are going to be the better "bang for buck" here.
Any suggestion on a cam?
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.... Difference between the 2: 5 CC.
1 CC = 0.006 milled off.
That's 0.030 the LS6 is already behind. Mill that off the LS6 heads and oh wait, mill the 5.3L heads and the LS6's are still behind 0.030.
In short, no, they cannot obtain the same compression ratio, and if 93 is plentiful, the more compression the better.
1 CC = 0.006 milled off.
That's 0.030 the LS6 is already behind. Mill that off the LS6 heads and oh wait, mill the 5.3L heads and the LS6's are still behind 0.030.
In short, no, they cannot obtain the same compression ratio, and if 93 is plentiful, the more compression the better.
Now my question to this is, why does Patriot offer a set of 243's at 59cc of 11.0:1, since that would be more compression then the 5.3's, to me that would seem that it can be done. And according to some people that posted the 243's have better flow than the 5.3, then it would seem to me that the 243's would be the better choice hands down....correct me if im wrong. im just trying to find out some answers as i too am debating on the 5.3's to the 243's
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My car made good low to mid range power with the 5.3 heads. My stock bottom end only made 45 less RWHP than my buddies 408 with the stage 2 LS6 heads with a M6. Go with the 5.3's.