377 vs 406?

[reamracing#08]

dirt track car(factory stock) which would you build and why? 3/8 mile tight corner long straights here are the motor rules

CARBURETOR
Holley 4412-500 CFM allowed. Stock carburetors must match make and manufacturer of car. Example: Ford-to-Ford, Chevy-to-Chevy, Mopar-to-Mopar. 1'' carburetor spacer allowed. Absolutely no alterations or modifications to Carburetors, EXCEPT removal of choke plate. No Holley 4BL. Altered carburetors will be CONFISCATED!

TRANSMISSION
Automatic Transmission: Must use stock OEM converter - no direct drives. 4'' wide flywheel, safety shield mandatory. Trans cooler must be shielded from driver.

Manual Transmission: 3 or 4 Speed OK (No 5 Speeds), No Internal Clutch Transmissions (Bert, Brinn, Falcon, etc), Mini Clutch OK. No Aluminum transmissions.

ENGINE
The engine must appear to be strictly stock for that model and make of car.

* NO ROLLER CAMS
* NO ALUMINUM INTAKES (CAST IRON ONLY)
* NO BOWTIE INTAKE
* NO ROLLER ROCKERS (ROLLER TIP ONLY)

Engine MUST be mounted on original stock mounts or solid steel mounts and in stock location. No limit on engine cubes. No engine setback, no frame notching for fuel pump clearance.

Clarification on intake manifold: The cast iron marine Bowtie intake will not be legal for this class. It was never installed on a vehicle from GM.

EXHAUST
Exhaust manifold will match the OEM style that the car came with.
Note: Center dump manifold were never installed on GM intermediate body cars or Camaro-Firebird cars.

FUEL
Any type regular pump gas is OK. Racing fuel is OK.e85 ok

IGNITION
Only stock ignitions. Steel gear on distributor - No Bronze gears. Must match make and model. NO aftermarket or dual point ignition systems. No MSD. No traction control devices allowed. Detection of traction control will result in being barred for life from all MSPA tracks.

WEIGHT
3200 LBS. MINIMUM. 73 - 77 GM Intermediate 3400 LBS. Added weight MUST be mounted in plain sight, painted white and must have car number painted on it. No cement or liquid style weights. Weights must be securely mounted with a minimum of two (2) �'' bolts with nuts and lock washers. Loss of weight may be grounds for disqualification. Use of mercury will be cause for lifetime suspension from all MSPA tracks.

[barnym17]

406, quadrajet carb.

[Mpcoluv]

Also it looks like a manual trans with a lightweight "Mini-clutch" would be an advantage also.
A brizinski iron intake would be the way to go also if they don't check for intake porting.
What are the cylinder head rules?
If they allow "factory" 4-barrell setups, you have a lot of leeway to make power it seems like.

[ZIGGY]

406 for the same reasons as when you were asking about a 327. And Mpcoluv is right - I'd jump all over that mini-clutch if allowed. (Looks like the usual dirt dobber dumbass wrote the rules.)
P.S.- I like and have run 377's with success in the right situations. A lot of drivers, including my son, like the "feel" of them on a slick track.
But in what I suspect is your deal, I wouldn't give away 30ci and torque. I'm betting the big motor will be easier for you to drive and for chassis setup. Plus the reliability factor - the bearing spacers you'll likely use and the extra rpm ain't particularly friendly to the kind of engine assembly and maintenance that many street stocks get.
As with your other posts, I'm just trying to help you. Good luck.

[BrazilianZ28Camaro]

About the fuels E-85 alone will corrode the carb pretty fast unless you can nickel plate it.....you could mix 50-50 with premium pump gas and go to 12 to 1 CR @ 377 cubes for increased durability in dirty track .

The 400 might bring the torque curve too soon and too strong in the rpm range and cause you off the corner traction problems.

Anyway this engine will be torquey, not a high rev monster...

My $.02



Diego

[reamracing#08]

yes we are allowed sticks with triple disk and light flywheels all of the intake and heads must be factory heads/intake must have came on a production car but no aluminum heads/intake there is no vacuum rules or lift rules but we are running Howards Cams 112082-05 with good success in the 355 we also are using 305 ho heads 601 casting that have been worked larger valves (1.94/1.60) also have a set of 441 (that are probley going on the new motor) 2.02 1.60 valves added to these but 76cc

[Mpcoluv]

You need to look at the Brezinski website.
"stock iron heads" gives you tons of leeway.Can you run Vortech heads? Iron Bowtie heads?
Someone made iron 15 degree heads for a while...
Also the fully worked cast iron intake from Brezinski is a pretty trick piece.

[reamracing#08]

yes i can run vortec but we are limited to factory intake and the intake is way off for carb intake vs vortec (also forgot to mention as far as bowtie none no intake/heads no marine stuff strictly automotive stock production)

[BigBro74]

cant u just egg out the holes on a old intake to make it work some way on a vortech head? or am i in left field on this one? never tried it.
Jason

[reamracing#08]

ive moded them for tbi heads but looking at the vortec i think they are way off

[BigBro74]

couldn't remember. changed a lot of intake gaskets on those vortecs but.....its been awhaile now
saw they have those bolt spacers/washers with some of the aftermarket intakes to run them with either style head. J

[Mpcoluv]

There is a cast Iron Vortec Q-jet intake out there.
I think you can have the casting numbers of your choice placed on them for those pesky tech inspectors.
After looking around, it seems like there is a large effort out there to skirt the "OEM Cast Iron" rules.
All it takes is a lot of money...

[Unkl Ian]

Does the track stay tacky, or does it become dry slick by feature time ?

Smaller motor might be easier to drive on a slick track.
If traction is not a problem, bigger is better(as long as you can feed it).

[reamracing#08]

slick is one way to put it

[Unkl Ian]

What combo wins the races now ?