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Discussion Starter · #1 ·
Hi, I'm just after everyone's advice on the following engine combo. I will be purchasing all the parts soon and just want to make sure I will achieve my goal - aiming for around 450Hp, with the ability to run 12 or if possible 11sec in my 67 Chevelle.

Here are my specs:
400SBC, 4.160 Bore, 4Bolt, splayed steel main caps.
SCAT FORGED 4340 STANDARD WEIGHT CRANKSHAFT, 3.750 Stroke
SCAT PRO COMP 4340 FORGED I-BEAM ROD, 6"
MAHLE PowerPak Pistons, 5cc valve relief,
Aiming for Compression to be just below 11:1
Edelbrock RPM Air-Gap Manifold
Edelbrock PERFORMER RPM WITH STRAIGHT PLUGS, 64cc.
Edelbrock - Performer RPM Street Fuel Pump
Comp Cams Solid: XTREME ENERGY™ Mechanical Flat Tappet Camshaft - XS274S
Comp Cams Pro Magnum Roller Rocker Arms, 1.6 ratio.
TCI 2500rpm Stall
Crane - Street/Strip Electronic Distributor
Milodon Pan Kit
Milodon Standard Volume Oil Pump

1. Are the heads compatible with the Cam? (I don't want to go to the Vortec).
2. Can I go to either a 3.800/3.875/4.000 stroke with no block modification?
3. Should I go straight or angled plugs?
4. Should I balance Externally or Internally?

Thanks!!!
 

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1. Yes
2. Keep the 3.75 stroke, pistons are cheaper.
3. Personally angled for easier access
4. I don't know.
 

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The cam and heads are right for a 355, a little small for a 406. The engine should make tons of torque though. I would step up the cam 1 and maybe go to a 200cc runner. Straight plugs its easier to buy headers for.

Dave
 

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NICE combo ,A BIT OVERKILL ,but hey insurance is good! the heads will limit your goals. step up to some 215 iron eagles ETC.ETC.ETCETC., AND you will have a nice street screamer . You dont have to run an internal balance ! your engine combo will live for a LONG time.;GOODPARTS.
 

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RPM Heads have 170cc intake runner....rite-sized for a healthy street 350 but only torque beast for a 400, the 170cc will run outa air....
You probably need 200cc or there about intake runner to feed a 400 properly
Too small a cam for a 400 and your power/ET expectations
A 2500 stall converter is pretty mild for 12s or possible 11s in a 67 Chevelle
Trans brake? What trans? What gear? What suspension mods? Slicks? DRs?
 

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I agree with larger heads.
My Nova ran 11.00 na & 10.30s on 150shot with Dart II sportsman heads that were 'breathed on'.

otherwise very similar to your eng.
 

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I had a similar combo before. I lightly ported the heads, more of a port clean-up than anything, and ran a similar spec roller cam. The engine would pull 16" of vacuum at an 850RPM idle, about 14MPG/23MPG driving like a sane person, and run mid 11's pulling 3400lbs when driving insanely. I drove the engine for 80,000 miles before tearing apart the entire car and drivetrain. Overall, I was very impressed with the engine since it was reasonable to drive every day and was very fast for daily driven car.

The Edel heads gave the engine good manners and a wide power band that worked well. A larger head that provides excellent velocity would be a better choice, but I believe that many of the aftermarket heads available then as well as today would have killed many of the better qualities of the engine when not at WOT. The modern AFR 195cc head would probably be a better suited head providing more top-end power without killing off low-speed efficiency or power.
 

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Discussion Starter · #11 ·
I will be running a strengthed Turbo 350, no trans brake.

3.55/3.73 gears in the rear - Haven't decided yet - still trying to keep it somewhat streetable, hence the 2500rpm stall.

I will be running some coil overs all around on standard 9" wide tyres.

Internally balance sounds great, I wanted to make sure it was ok with the SCAT crank. So it looks like a can use a standard 350 Balancer on the front - I will be using a TCI version.

I have just got recomended by AFR to use a 210cc head. Will i need to change the springs on this assembled head? Are these known vortec heads?

Piston price is not an issue, so would I be able to go to either a 3.800/3.875/4.000 stroke with no block modification?
 

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Even running a 5.7 rod you may have some clearancing issues, not as much if you were using a 3.875 or a 4.000 crank. The rods bolts can be an issue you will need a small base circle cam. The AFR head is not a vortec design, just specify your cam you are using when you order your heads, being either solid/hydraulic roller or solid roller.

Dave
 

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Discussion Starter · #13 ·
Even running a 5.7 rod you may have some clearancing issues, not as much if you were using a 3.875 or a 4.000 crank. The rods bolts can be an issue you will need a small base circle cam. The AFR head is not a vortec design, just specify your cam you are using when you order your heads, being either solid/hydraulic roller or solid roller.

Dave
I'm planning on running a 6.0" SCAT I beam rod and I have read that their rods are stroker clearanced for this kind of application.

Since my block has already been machined up and ready to go, I am trying to find out if I can put a longer stroke crank in it without doing any block mods.

Someone mentioned going up to the next cam, but what are peoples thoughts on it: XS282S
I am still trying to keep this motor kind of streetable...........
 
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