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Discussion Starter · #1 ·
I have a 7,000 pound K10 D44/FF14 bolt TH350/203 4.10 and 38's and need to build an engine suitable for it. I was throwing around the idea of a 406 SBC since I have a bunch of 400 sbc stuff lying around instead of swapping to a big block. Now i'm wondering if besides a Vortec head with more modern head designs if there is a better low rpm torque head that would work i would hate to spend a bunch of money on heads and not get the same results as the el-cheapo Vortec, or if just moving up to a stock 454 would be more reasonable in my quest for torque. At any rate here is the 406 recipe tell me what you think.

Stock 4 bolt 400 block
4.155 bore 3.75 stroke 5.7 rod
9.5:1 compression
Vortec Iron heads with upgraded springs
Edelbrock Performer RPM Air Gap
Holley 3310 750 cfm vacuum secondary
Lunati Bracket Master II
292/292 dur. .480/480 lift
1.5 Roller Rockers

From what I have come up with it should put out 525 lb ft at 3,500 rpm and 428 HP at 5,000 rpm, with torque around 472 lb ft at 2,400 rpm. Any sugestions on cam or heads to get even more torque lower would be helpful, unless this should be enough power for a vehicle of that size. I would hate to build it and be unhappy with the output.
 

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you can always step up to an aluminum aftermarket head. I like AFR's but your choices are unlimited. Vortecs are a good stock style head. but if the extra money isnt a big issue I say get some aluminum heads.
 

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you can always step up to an aluminum aftermarket head. I like AFR's but your choices are unlimited. Vortecs are a good stock style head. but if the extra money isnt a big issue I say get some aluminum heads.
I figured you would have said BBC!:D Lol...


Just mod a set of stock Vortec heads for more lift.

SDPC sells some ready to go.
Upgraded Vortec head kits - features our high performance Z28 valve springs with light weight LT4 retianers, good for about 0.550" lift with a hydraulic camshaft.

http://www.sdparts.com/catalog/engi...rheadsandheadkits/UpgradedVortecHeadKits.aspx
Upgraded Vortec Head Kits
 

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Are you sure the intake ports are large enough to feed a healthy 406? Aren't they roughly 170 cc or something?

Anyway, for my 406, I am using the Dart Platinum Series heads with 200 cc intakes. We are building this thing for torque. I am hoping for high 500s at a useable RPM.
 

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Discussion Starter · #5 ·
Cool let me know how the Dart 200cc heads work on the 406, it will be a few months before I even get to start on it anyways seeing as how I am in Iraq! I'll be in the Houston area in the next 60 days or so though so let me know how it goes if you can get High 500's at a useable rpm that would be great.
 

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if low speed torque is your goal, the vortechs are perfect for this combo.

instead of getting some from the boneyard and having them cleaned up and replaced with new springs, i would opt for the ready to go vortechs from scoggin dickey that come already set up for .550 lift and come with screw in studs.

if you opt to go the bone yard route, make sure the shop has done vortech heads before. some head rebuilders don't know how to properly shim vortech heads on the spring seats, especially when planning to use a high lift camshaft.

remember to also drill the steam holes for proper use on the 400 sbc. if you buy the heads from scoggin dickey, just ask them to drill the holes for you, an extra 75 to 100 bucks.

i would also not use the elebrock air gap performer, why use this manifold if you are really not going to make power over 5500 rpm. i would stick with a performer intake.

if you are going to use 5.7 rods, instead of the factory 5.5 rods that come in all 400 small blocks, make sure that the block is clearanced properly to accomodate these rods. if you also use the 5.7 rods, you are going to have to use a cam with a small base circle to clear these rods around the cam.
you might not have to use a small base circle cam if you clearance the rods, if you go this route, remember to have the whole rotating assemly balanced.

if you keep the rpms below 5500 rpm, your cast rotating assembly should live a long torquey life.
 

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That cam will be more of a midrange to top end cam. 292 duration is quite large for a torque cam. What is the lift at 0.050.

I would look into the newer designs of cams like the VooDoo or the Comp XE they have newer profiles and shorter overall durations with the same 0.050 numbers. This will equate to more cylinder pressure with the same 0.050 duration and lift which equals more power.

If you are looking for a lowend torque cam I would be looking at less that 276 overall duration.
 

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torque numbers seem a bit large.

I'd look at a lower duration roller cam and some port fuel injection.
 

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I would sugguest a Comp Cams 268 cam as a good all around cam that should rev to 5500 with good heads. The Vortecs will work but have them modded if you go with more lift than the cam you specified. I believe the 268 cam is around .454 lift but I'd recommend 1.6 roller rockers depending on heads you go with. AFR aluminum 185cc heads would make a nice boost without killing your low end if you can afford them. The Performer RPM air gap should work ok since you have the hood clearance. I think you might be a bit high on your torque and HP quotes unless you go with the aluminum heads. Big Block with the same cam mentioned above will make more torque and HP so that will be a better route if your truck really does weigh in at 7000lbs.

Jason :)
 

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That 406 you are talking about is the Impersonator from CHP. Its a sweet build and I used it for a basis for my motor in my 69 Camaro. But I used AFR 195's and a more modern Comp fast ramp solid cam. As far as for your truck I think a Caddy 500 or 454/496 Chevy would be a better route to take. Just gonna make more torque down low to help you move all that mass around.
 

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Discussion Starter · #12 · (Edited)
Ah ha i found the cam card for the Lunati cam since the duration seemed a bit long at .050.

Duration @.050 IN/EX: 230/230;Lift IN/EX: .480"/.480";LSA / ICL: 109/107;RPM Range: 2000–6000 :mad3:

althought i'm now looking at the Voodoo 268 cam
Duration @ .050 IN/EX: 227/233;Lift IN/EX: .489"/.504";LSA / ICL: 110/106;RPM Range: 1800–6200
 

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Discussion Starter · #13 ·
Well thanks for everyones input but looking at the prices of complete take out 8.1 liter 496 big blocks I think i'm going to go in that direction hard to beat driveability and TORQUE!!!! Although any input on the trickey parts would be appreciated.:smokin:
 

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Well thanks for everyones input but looking at the prices of complete take out 8.1 liter 496 big blocks I think i'm going to go in that direction hard to beat driveability and TORQUE!!!! Although any input on the trickey parts would be appreciated.:smokin:
"there is no replacement for displacement":smokin: Seriously look at pullin a 454 out of a suburban, you can find them for dirt cheap. Even if you did have to rebuild it, it would probably still be cheaper than an 8.1 pullout.
 
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