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Discussion Starter #1
I have a 434 SBF that is way behind in the power and e.t. dept. The motor is 11:1 pump gas. Car runs 6.6x 1/8mi on motor, depending on 60' times mph is 104/5 range. I'm wondering if I my cam is too large for my heads or if I need some more compression. Lift is .7xx plus on both sides. This engine makes peak power at 6200 rpm, I was thinking it should be in the 7200-7600 range.

What should I do first? Leakdown check?
 

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Discussion Starter #2 (Edited)
These numbers are off of the Brodix website. The 1st number is .100 lift going to .700

STS T1 F STD 225
(CNC Ported)

2.100 Intake

147

215

262

303

324

333

334

1.600 Exhaust

119

161

190

203

213

216

221
 

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What are the cam specs, what intake/carb, what gear, weight, trans, etc????
 

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did you want to keep it pump gas? if not deff more compression for those heads. 14:1
 

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Our old 417" combo made 711 @ 6800 with the same heads you are using. We had 14.5:1 compression. The cam was 274/288 @ .050 .763/.735 lift. How much duration does your current cam have?

+1 on more compression.
 

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Discussion Starter #7
We haven't found the cam card yet. Lift was around .750 on both sides and lobe sep. was 110. The duration I can't rememeber. I'm going to call and get the specs today. The carb is a fast 4 hole throttle body. The previous carb was a C&S aerosol. We dynoed the car with 3 carbs though the C&S was in the middle on power, with the highest being a "dyno ringer" Quick Fuel.
 

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With an engine that size and if those are out of the box Track 1s that is about right as far as rpm for that engine. If you want that thing to make peek power above 7000rpm you need the heads ported and a mcsa of at least 2.65 those heads will go out to 2.84 mcsa and still have good air speed and flow numbers in the 350s on the intake and 260 ex with air speeds above 275 fps when done correctly. We have done a lot of testing with these heads as we run the Fcasting which comes with the exhaust port raised. These are the heads that we ran on our NMRA renegade nitrous car and Brain Mitchells blower car. If you have any questions feel free to call me @423/479-3232. InLiberty Dan
 

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Oops. The intake is a Super Victor.
3.73 gear with a glide and 26x10s
Car weighs 3200-3250.
damn, this is your problem. make this car 1/8th mile only and put some rear gear in it!!! your converter should go close to 6000 rpm if you shift in the 7000-7200 range.
 

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If the engine is making peak power at 6200 rpm and he is only running a 26 tall tire I don`t think gear or a 6000 converter will help much. In Liberty Dan
 
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