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Discussion Starter · #1 ·
So I have molnar 4" crank, power adder rods and cp flat tops coming in next week. Building a 408. I have 823 castings and new ferrara valves. I'm shooting for an honest 650-700 hp. I also have holley dominator efi system. What intake should I go with? Also opinions on lifters. Trying to set up for 10.0 index with some street use. Thanks, Steve
 

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Discussion Starter · #2 ·
Also having a local shop port the heads. They have a good reputation for porting.
 

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Banksters Paradise
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Vic jr or super vic does very well on the square port heads. Trying to hit 700hp i'd personally go super vic with a 4500 TB.

Being a 4" crank (408) you won't have to spin it over 7500rpm to make the power so a big hydraulic roller will work well, and the money you save on needing adjustable rockers and solid roller lifters, you can spend it elsewhere to extract more HP's.

Lifters i personally use oem low mile GM take outs, carefully inspected for any faults and cleaned out thoroughly. As i firmly believe they are better quality than all the aftermarket sold GM lifters now days, including the gm ls7 lifters.

Look at this car below for example....read the description, he used a new set of oem GM lifters in this build, but back in those days when this car was built, the replacement lifters you received from a GM dealer were the exact same lifters that GM had put in their ls1/2 engines from the factory. That is not the case now days, just because they're boxed as GM brand lifters, they're not the same OE quality.
Quote from article above: "With a solid bottom-end built, Coleman turned to Brian Tooley at Total Engine Airflow (TEA) in Tallmadge, Ohio, for cylinder head expertise. A fresh set of GM LS6 heads were utilized and were subjected to TEA's Stage porting. After enlarging the combustion chambers to match the 4.00-inch bore and extensive CNC-porting, the heads were milled to 62cc in order to achieve an 11.5:1 compression ratio. After receiving new seats and guides, Manley stainless valves, measuring 2.08 and 1.60 inches respectively, were fitted and a competition multi-angle valve job was performed, allowing the heads to flow 325 cfm at .600 lift on the intake and 260 cfm on the exhaust. Comp cams 921 double springs and titanium retainers along with Thunder Racing 7.3750-inch hardened chrome-moly pushrods work in conjunction with a fresh set of stock hydraulic roller lifters and GM 1.7 rocker arms to swing a custom Thunder Racing/Comp Cams hydraulic roller camshaft. Although the cams specs are proprietary, guess above 280 duration at .050 with Mothra-like lifts approaching .800, and you will be in the ballpark."

Also i'm personally spinning oem ls1/2 lifters to 8000rpm. Previous engine i'd shift it at 7600-7700. This new engine in vid below i'm shifting right at 8k, give or take. I run a quality 15/40 diesel oil. And what i just told you there are plenty of turbo LS guys doing the same thing, diesel 15/40, and 8000+ rpm on stock lifters. Now, you can say their cams aren't radical (because turbo), but look at Coleman's old camaro above, above [email protected] .050 and near .800 lift on heavy comp 921 doubles, with oem gm hydraulic lifters. And my cam is 243/250 .660 108lsa. The lifters are the last thing i worry about. Can one possibly fail? maybe, but probably so can the gen4 rods at 8k rpm with enough cycles on them. We're not circuit racing, car only sees high rpm's for few seconds at a time. If you want to spend thousands on solid roller setup for a stuff all gain, and use aftermarket lifters that can fail just as easy as OEM, you can. I tell ya the hydraulic lifter has a little cushion at high rpm and let's everything live.. but don't let me stop you from going solid.

This vid is only 91% throttle and not anywhere near fully sorted yet, just a bit of shakedown run.. Camaro LS2 drive
 

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ls1 s/s notch on 28s
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vic jr is as good as a 4150 super,holley split is is as good as a 102mm hi-ram on a 427ci deal..its the intake i was going to use on my ls3 headed deal until i got sick of waiting so i bought a holley sniper twin 4150 sheetmetal deal on clearance..

cam wise a hyd roller will get you there fine..contact ed curtis an he can set you up,theres a bunch of good cams that should get you in that range..cam an intake just need to match your goals..larger stroke will want a later ivc vs stock an then port speed will change it to a tad earlier being more eff. on cyl. fill. then carb or injection an desired rpm an so on play in.

but my deals meant to go 7800rpms,ls3 valves,pac .650 springs,comp short travels hyd lifters and then a 239/255 comp lobed cam..its one on their hybrid hyd/ solid roller style type lobes that has a slow ramp rate an .638 lift.
 

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Discussion Starter · #7 ·
I have ferrara valves, which I know the intakes a fairly heavy. I don't have a problem replacing them with something lighter. Don't want to spend the $$ on titanium though.
 

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ls1 s/s notch on 28s
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I have ferrara valves, which I know the intakes a fairly heavy. I don't have a problem replacing them with something lighter. Don't want to spend the $$ on titanium though.
a huc style intake lobe would do fine with them an do like a ehi exh lobe
 

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So I have molnar 4" crank, power adder rods and cp flat tops coming in next week. Building a 408. I have 823 castings and new ferrara valves. I'm shooting for an honest 650-700 hp. I also have holley dominator efi system. What intake should I go with? Also opinions on lifters. Trying to set up for 10.0 index with some street use. Thanks, Steve
What's your weight. I have been trying to get their with a 408 at 3250. Best so far is 10.15 with -500 da.
If you do get their I would love to know your cam specs.
Good luck and keep me/us updated
 

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Discussion Starter · #10 ·
I'm starting the build, 67 mustang coupe. Goal is 3000-3100 w/driver. Got a friend Thats using GM ls3 cnc headed 408. he's about 3380, used his big block 10" converter and has been 10.teens in so-so air.
 

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650 to 700 fwhp with a 408 is Pretty Easy. Question is What's your Rpm peak to Help pick the Intake. Also what compression.

650 hp can be done with a Factory style Plastic intake as well 700 hp with a 408 with Compression. Higher Rpm 7k+ would want a Single plane.
 

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Discussion Starter · #12 ·
650 to 700 fwhp with a 408 is Pretty Easy. Question is What's your Rpm peak to Help pick the Intake. Also what compression.

650 hp can be done with a Factory style Plastic intake as well 700 hp with a 408 with Compression. Higher Rpm 7k+ would want a Single plane.
Thinking about the holley hi ram
 

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Discussion Starter · #13 ·
Don't know if the low ram would be a bit much. Like to be in the low to mid 7000 range.
 

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High Ram or any Decent Single Plane 4500. 4500 TB is worth a few Hp's over a 102/105mm TB.

Low Ram is For 1 or the 2
8500+rpm NA or Forced Induction.

Side note to Remember 👇
in All Reality the High Ram Doesn't have Enough Plenum with the use of the 105mm top. + The air Likes Coming from the top Vs the inlet in the Front where air has to go Across all the the other runners to reach the Rear. Just something to Ponder, And the Ls3 intake Test? Super Vic 4500 vs Holley High Ram with a 105.
4500 won 🤫

Solid Roller used with a 408 could and should get 700 fwhp + 4500 intake with Decent Compression.

13+ Compression Same Solid Roller and a plastic intake should produce similar results.



I based my own Hp ideas on this Guy's build. More Comp, more Cam etc.... Good Guy also. Btw the engine Owner is Steven and Works @ Cam Motion.
😉
 

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ls1 s/s notch on 28s
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Im talking about as used on top of a 4150 not with hi ram lid an yep no sharp turned..the 102mm sniper on gpi test you can see how far the runner went into the plenum oddly though my twin 4150 topped sniper efi sheetmetal deal the runners are flush to the bottom of the plenum vs sticking out above like a stack set that got a top boxed on it an 102mm inlet
 

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Discussion Starter · #17 ·
High Ram or any Decent Single Plane 4500. 4500 TB is worth a few Hp's over a 102/105mm TB.

Low Ram is For 1 or the 2
8500+rpm NA or Forced Induction.

Side note to Remember 👇
in All Reality the High Ram Doesn't have Enough Plenum with the use of the 105mm top. + The air Likes Coming from the top Vs the inlet in the Front where air has to go Across all the the other runners to reach the Rear. Just something to Ponder, And the Ls3 intake Test? Super Vic 4500 vs Holley High Ram with a 105.
4500 won 🤫

Solid Roller used with a 408 could and should get 700 fwhp + 4500 intake with Decent Compression.

13+ Compression Same Solid Roller and a plastic intake should produce similar results.



I based my own Hp ideas on this Guy's build. More Comp, more Cam etc.... Good Guy also. Btw the engine Owner is Steven and Works @ Cam Motion.
😉
I actually read that build last week. Kinda why I was contemplating on a tight lash solid.
 

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Holley High Ram 105mm Lid
Summit Price: $780 (plus TB)
Construction: cast aluminum
Throttle opening: 4.140 inches
Throttle body size tested: Holley 105mm
Fuel rail: Holley
Injectors: Holley 83 lb/hr
Peak power: 612.6 hp at 6,900 rpm
Peak torque: 509.7 lb-ft at 5,000 rpm
Ave HP (3,100-7,000): 462.3 hp
Ave TQ (3,100-7,000): 476.3 lb-ft
TQ at 4,000 rpm: 458.7 lb-ft

*Edelbrock Super Victor 4500
Summit price: $541
Construction: cast aluminum
Throttle opening: 4500
Throttle body size tested: Accufab 4500
Fuel rail: Edelbrock
Injectors: Holley 83 lb/hr
Peak power: 613.8 hp at 6,900 rpm
Peak torque: 504.2 lb-ft at 5,700 rpm
Ave HP (3,100-7,000): 455.2 hp
Ave TQ (3,100-7,000): 467.8 lb-ft

*Holley Hi Ram (dual 4150)
Retail price: $781 (plus TBs)
Construction: cast aluminum
Fuel rail: Holley
Injectors: Holley 83 lb/hr
Peak power: 619.9 hp at 6,900 rpm
Peak torque: 515.3 lb-ft at 5,500 rpm
Ave HP (3,100-7,000): 465.1 hp
Ave TQ (3,100-7,000): 477.9 lb-ft

1 good 4500 TB @ 2000+ cfm covers X 2 4150's also no need of X2

Its cool if you want Dual TB or in the Need of Dual TB's. If placed over the Runner it ='s Extra Hp. The GPI basic test never tried the Holley with a 4500 top but in the Video it's said it made more Tq and Hp up until the 7500-7800 rpm mark With Dual 4500 TB"s. The engine was Wanting Ls7 head 376 cubic inch 8800 rpm Air/Cfm.

i believe this read tells me a good 4500 would = to the 4150's used maybe not as good because of how the X2 TB''s sit over each Runner, but with a Good lid I'm Sure we could get something along the lines of the dual X2 4150'$. . just needs a Cherry on top Lid for a 4500. 👍

X2 4150'$ (Vs) X2 4500'$

747fwhp (vs) 754fwhp +3 lbs of Tq @ 624.

 

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I have the Super Vic and was Told to Use the High Ram by Teacher: Aka ER Racing it's easier and cheaper to port with somewhat Perfect Downward Runner's.

Ls3 gets the SV4500
Ls7 gets the High Ram

Same 4500 used.
 

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Discussion Starter · #20 ·
I certainly appreciate all the input fellas. Feel free to keep it coming as I haven't ordered intake or cam yet.
 
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