anyone have and good head, cam, intake, compresion combos for a 406. This may seem like a broad question but id like to work with a factory head casting, (basicly one i can afford). Ive heard of a casting of the last 3 digits 441 with a 2.02 valve as being good, is this correct? As for intake, cam, and carb, ill probly run a single plane manifold and 750 carb. Thanks for any info

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I believe 441X has 80cc chambers which would allow streetable compression ratios with a flat top 406. Any of the 76cc heads can be opened up to 80cc's.
After heavy porting and 2.02x 1.60 valves they will work well. Look for the pre '74 thick castings.
Dart sportsman II's are available in 72CC
chamber size and can easily be opened up to
what ever chamber cc you need. They will need a lot less porting to reach decent power
and are beauti HD castings. You'll have to weight out the cost/benefits as to which is better. I'd go with the Sportsman's or a set of Canfield's for a serious power cast iron motor.
For a cam: Go with an Extreme Energy XE284H-10 240/246@.050-.507/.510" lift on 110LSA
use 1.6 rockers and good springs to match.
This is a rough idle cam and will need a 3500+ stall converter and 4.10's but will go like stink...

[This message has been edited by F-BIRD'88 (edited November 10, 2001).]

[This message has been edited by F-BIRD'88 (edited November 10, 2001).]

 

What kind of gas mileage do those engines get? I found a Pontiac 400 for $250. How much more will I use from my 305 now?

 

The motor combo I outlined above would not be that great on mileage 'cause of the aggressive cam.
Based on the CID difference alone the 400CI
motor would lose about 5 to 10 Mi/gal when compared to a stock well tuned 305.
The 400 pontiac can be built/modified for
great street performance in a third gen
while having reasonable mileage. I would use
good flowing moderate port volume heads like the performer RPM pontiac heads. either a edelbrock performer or factory pontiac
dual plane intake (pre 1973) Factory pontiac Q-JET, 10.0:1 cr.
A mild hydraulic cam like the factory pontiac "S" cam or one of the EXtreme Energy
grinds would work well for this. Use an overdrive trans Th700r4 (adapter) or a TH200-4r (BOP) and a 3.xx gear. A th350 (BOP) and 2.73's or 3.08's would work well too. Small tube pontiac headers and a hi-flow exhaust.



[This message has been edited by F-BIRD'88 (edited November 12, 2001).]

 

Stock iron heads you're limited to about 10:1 compression even if you use a fairly aggressive cam to keep cylinder pressure down. Stock casting don't take kindly to massive compression.

I don't know about 80cc stock heads. 76cc is as big as I beleive they ever went, even on the low-compression 400s. The factory used massive 24cc dished pistons to keep the compression low in those motors.

Anyway, with flattops and a 76cc head you'll be right around 10:1. I ran a combo like this and a mild 270* grind cam and it was too much compression for pump gas. Made good power- 13.3s @ 103 on the motor with a stock converter, generic dual plane intake, QJet 4bbl, 2.92 gears and street radilas so I would say it worked well, but got annoying buying race gas to really use all of it. If I had it to do over again I'd get some 18cc Keith Black D-Dish hypereutectic pistons and run a more performance oriented set of Vortec 64cc heads and intake. You'd still be around 10:1 with this combo.

The Vortecs will tolerate the high compression much better than older style heads and will make more power anyway.

FYI- If you want to step up to a real bargain in performance heads for a few bucks more then look no further than a set of Dart Iron Eagles. They work a lot better out of the box than the Sportsman IIs (better exhaust port by far) but don't cost any more. They come in 64 and 72cc chamber sizes and intake port volumes of your choice. I swapped out my stock 76cc heads for a set and right out of the box instantly went 3 tenths and 4 MPH faster with no other changes.


[This message has been edited by Damon (edited November 13, 2001).]

[This message has been edited by Damon (edited November 13, 2001).]

 

I have freshly built 406 sbc 4 bolt main w/ brand new GM Performance heads 64cc (p/n 3991492) 2.02, 1.60, Manley stainless steel race flo valves, Harland Sharp roller rockers, Comp cams hardened push rods,TRW forged flat tops w/ 2 valve reliefs giving me 10.92 comp. ratio, Edelbrock Performer RPM manifold,Edelbrock 750 carb, Edelbrock fuel pump(street)Pete Jackson gear drive(quite), Summit Stage 2 rods, Steet Dampr, Milodon windage tray. Whole Engine assembled with ARP bolts. Is this a good set up for late 80's Z28 w/ 700r4? What would you change?

[This message has been edited by Skolnik (edited November 30, 2001).]

 

A bigger displacement engine needs to flow more air to fill the cylinders. Although you can use old factory style heads, don't expect big gains with the bigger engine. Putting a big cam in will help but the heads will still be a restriction.

 

The heads I have are 64 cc. What heads do you recommend?

 

This is my current 406 build up(in progress)
406 Keith Black Silvo lite Pistons (about 10-10:5 comp)
461 double hump heads, 64cc 2.02/1.60 bowl hogged, port matched, magnum roller tip rockers
Edelbrock RPM or Weiand Stealth Intake(i have both, which ever runs better)
Hooker Super Comps 1 3/4
TH700R4 with 3.42 Posi(looking for 3.73's)
The cam I havent decided on. I was looking at the 274xtreme cam, 230/236 274/286 .487/.490 lift 110LSA
Comp Cams recomended a 284xtreme, in my opinion thats way to freakin big for what i want. in hot rod they did a 406 build up with sportsman II heads and the 284xtreme cam and IMO got sh^&&* power numbers, they said the should have went with a smaller cam and had made more power. I would like to spin it 5800-6000 rpms
Motown has some new heads out for 383-400cid engines and they are freaking awesome.
Sorry this was so long, hope it helps some.
LilJay

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Wide Open Till You See *** ...Then Brake

89 T/A Clone
406 in progress
TH700R4 3.42 Posi

 

WITH A SINGLE PLANE, YOU ARE PLANNING ALOT MORE RPM THAN I DID WITH MY COMBO. I HAVE A 86 TRANS AM WITH A 406. STOCK CRANK, 5.7 RODS, SPEED PRO PISTONS (CR 9.3 BURNING GASOHOL, 89 OCTANE AT $1.04 A GALLON TODAY), A MILD COMP CAM (HYDRALIC) WITH ROLLER TIPPED ROCKERS, WORLD S/R TORQUER HEADS (VALVES 2.02 / 1.60), RUNNING THRU SLP 1 3/4 HEADERS, SINGLE CAT (HI FLOW, 3 INCH IN/OUT) ENDING IN A DYNO MAX SUPER TURBO. I RETAINED THE STOCK TPI BUT WITH LARGER INJECTORS. REAR GEARS ARE 3.27 WITH 255/50R16 TIRES AND TRANNY IS 700R4 WITH A SHIFT KIT. I USE STOCK SHIFT POINTS AT 4500 WOT. I BUILT IT THAT WAY TO BE A HI-TORQUE, LOW RPM ENGINE. ALL POWER FOR THE STREET. SOMETIMES IN THIRD GEAR YOU THINK YOU ARE STILL IN SECOND. THE 2-3 SHIFT WILL BUMP YOU HEAD BACK AGAINST THE HEAD REST IF YOU ARE NOT PAYING ATTENTION. IT STARTS AT 45 IN 3RD GEAR AND JUST KEEPS CLIMBING PAST 85 WITH NO LETUP. CRUSING ON THE FREEWAY, I GET 17MPG JUST LIKE THE 305 DID. I HAVE NOT ADDED MY NEW COMPUTER CHIP YET.

FOR HEADS, CHECK THE WEB SITES FOR FLOW NUMBERS AND YOU WILL SEE THE FLOW AT 100 & 200 ARE ALMOST THE SAME FOR EVERY HEAD. AT 300 THEY START TO SEPERATE AND THE BETTER HEADS JUMP BY LEAPS AND BOUNDS. I THINK CHEVY HIPERFORMANCE MAGAZINE WEB SITE HAS A LIST WITH HEAD FLOWS. I USED A DESKTOP DYNO TO COMPARE CAMS AND HEADS. YOU WOULD BE SURPRISED HOW LITTLE DIFFERENCE 6 DEGREES MORE ON A CAM, OR USING A 1.6 ROCKER MAKES. BUT KEEP WORKING AND YOU WILL FIND THE COMBO YOU WANT. MY COMBO SERVES ME JUST FINE AS MY DAILY DRIVER AND IS LOTS OF FUN ON THE STREET. JUST DECIDE WHAT YOU REALLY WANT OUT OF YOUR CAR, AND HOW YOU WILL DRIVE IT.

 

I HAVE A 406 10.3 TO 1 COMP RUNS MID 11S ANG GETS 22 MPG ON HIGHWAY AND 16 AROUND TOWN