243 Heads Vs. 706/862 Heads on Turbo 5.3L
07-07-2014, 01:48 AM
#1
243 Heads Vs. 706/862 Heads on Turbo 5.3L I have been doing tons and tons of research on this website along with reading the forced inductions page like crazy for the past 6 months. I think I have finally decided to go the turbo route. Being a broke college student, I will most likely jump on the junkyard 5.3l bandwagon lol. Okay the plan is (sounds good in my head right now lol):
- Stock bottom end 5.3l (hoping 07+ for stronger internals)
- possibly rod bolts
- 243 heads or stock 5.3 heads (not sure, that is my question I have)
- New valve springs
- Thinking E85
- NO intercooler if going E85
- 120lb injectors
- Fuel pumps (not sure yet???)
- head studs
- LS9 gaskets
- Custom grind cam (might use stock cam for a little bit though)
Not exactly sure on the turbo details/dimensions, will have to talk to a representative for that, but I am leaning towards a BW S400 (S475 most likely) series if the wallet allows it. If the wallet doesn't allow it, ill settle for a On3 76mm.
Sorry for the long post of details but figured you guys would need to know about the combo I have in my head for this question.
Will I make more power and/or make power more efficiently with 243 heads on the 5.3l or with the stock 706/862 heads? I will port either head that I chose down the line.
I am not shooting for the sky. A fun street car that I would like to run low 10s in (possibly very high 9s?) but it will see more street/highway than the track. I would be happy with 650-700rwhp through a stalled auto. I will run however many pounds boost it takes to get me there.
Any help would be appreciated and or any advice on the combo/setup I have in my head. I am still learning a lot and doing my fair share of research so feel free to correct me where I am wrong. Thanks,
Nate.
- Stock bottom end 5.3l (hoping 07+ for stronger internals)
- possibly rod bolts
- 243 heads or stock 5.3 heads (not sure, that is my question I have)
- New valve springs
- Thinking E85
- NO intercooler if going E85
- 120lb injectors
- Fuel pumps (not sure yet???)
- head studs
- LS9 gaskets
- Custom grind cam (might use stock cam for a little bit though)
Not exactly sure on the turbo details/dimensions, will have to talk to a representative for that, but I am leaning towards a BW S400 (S475 most likely) series if the wallet allows it. If the wallet doesn't allow it, ill settle for a On3 76mm.
Sorry for the long post of details but figured you guys would need to know about the combo I have in my head for this question.
Will I make more power and/or make power more efficiently with 243 heads on the 5.3l or with the stock 706/862 heads? I will port either head that I chose down the line.
I am not shooting for the sky. A fun street car that I would like to run low 10s in (possibly very high 9s?) but it will see more street/highway than the track. I would be happy with 650-700rwhp through a stalled auto. I will run however many pounds boost it takes to get me there.
Any help would be appreciated and or any advice on the combo/setup I have in my head. I am still learning a lot and doing my fair share of research so feel free to correct me where I am wrong. Thanks,
Nate.
07-07-2014, 08:15 AM
#3
Thank you for the feedback Monmouth. I figured the 243s would have been the better option since they do flow more but for some reason I was thinking when boost is added to the equation, all those "flow numbers" get pushed under the rug. I don't know what I was thinking, that's for the clarity lol.
