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Author Topic:   406 or 350
Dirt Maniac

Total posts: 103
posted February 04, 2005 05:48 AM  
I run on a real short track. I have a new set of 441 heads that have been milled to 68 cc and have 2.05-1.6 valves. Which will run better a 350 or 400? I run a 700 final and around 6300 rpm. I need to get hooked and out of the corner faster. The track is very inconsistent between dry slick and tacky. Toward the end of the season it tends to be more dry slick. I run a 350 with 305 heads now and get out pulled out of the corner but beat them the last half of the track. We also donot have a weight limit. I have 2 400's and two 350's with plenty of short block parts so the short block is not a money problem. Any idea what cam to run?

Dirt Freak

Total posts: 238
posted February 04, 2005 06:52 AM  
I would think the 441 head intake runner would be too small to feed a 406.(??) I ran a 355 with the 441 heads on a 4/10 mile track last year with a 4412 2bbl and it seemed to do O.K. Got 7200 rpm out of it with a stock cast iron crank and stock rods once we got the ignition squared away. Our problem was our gear. We were running a 6.20 and getting pulled in the straights.

Dirt Freak

Total posts: 226
posted February 05, 2005 09:55 AM  
I run with a 355 now and get pulled by the 406's, I would go with the 406, seems that most people say no replacement for cubes


Dirt Forum Champ
Total posts: 874
posted February 05, 2005 10:12 AM  
you don't have enough gear, try more then a 7.0... or re cam the motor you have. If you can beat them anywhere down the straight you have more motor then them, just not geared or cammed right

Dirt Freak

Total posts: 333
posted February 05, 2005 11:09 AM  
Ditto to extreme12x. That was my problem last year. Not enough gear. Beat 'em in, through and coming out of the corners and into the straights but they pulled me (for a short distance) down the straights. Cam is a big factor also, but those 305 heads are probably your short-coming. Can you run after market? Big intake valves, rather big combustion chambers, all on a set of heads that just won't flow that well. On a dry slick and a short track, I'd stick with the smaller cube motor, with a decent set of heads (aftermarket, 200cc intakes runners and 64cc comb. chambers or smaller depends on comp ratio you want/need), work your gear ratio to max out the limits of your motor and set the car chassis up like a bad boy!!!

The other side of the coin. Big cubes, and lots of new tires! You can be fast for awhile with all that big torque and horsepower, but with a dry slick those tires will glaze up pretty fast! Too much can be too much. Everyone has their opinion, this is just mine. Race on.

if it ain't fun, then don't run

Dirt Maniac

Total posts: 103
posted February 05, 2005 06:09 PM  
I understand what you guys are saying and here is the factor on my gearing. Everyone else is running from a 700 to a 788 gear and I am running a 688. Once I get to the front they can't catch me because I can get alot more speed and my car is capable of pretty well handling any thing I can throw at it in the corners when it is tacky. But my problem is when it goes dry slick, I can't hit the corners as hard and they can run the bottom of the track. That is why I was wondering about the 406 and staying with my gears. I don't run a 9 inch rearend, I wish I did.But I was considering going to a powerglide tranny and a 9 inch so I could run a 713 gear and a little bigger tire. We cannot run aftermarket heads so the 441 is what I will haft to use. I am building a new car this year with a set back cage so I will have 2 cars. I just don't know rather to spend the money on a 406 or go with another 350 to match up with these heads. I do like compression but the engine builders said I can build just as much power with these 441's and flattops as I can with the 305 heads. We only run 10 races a year at our track so it is important to try to hit it the first time out.

Dirt Maniac

Total posts: 130
posted February 12, 2005 11:13 AM  
We run on a 3/8 mile track that usually goes dry-slick. We use a 377. Reason is that you get more hp and torque than 350 or 355 and you can still twist the snot out of the motor. Should pull to end of the straight and beyond. Find a combo that will give you a 700 to 720 final. Talk to the cam co.'s, they know their stuff. Also talk to someone who knows carbs inside and out, 'cuz jetting, power valve (yes, run it), accelerator pump and accelerator cam profile in the right combo will give you the snap you need off the corner. If your track stays fairly smooth you can use a soft set-up for the rear and e-z up shocks for the front. We run 175 springs in the back with Pro Shocks that are #WB 95. One more thing: what's your cross weight and rear percentage? All of this will help get you off the corner and down the straight without losing what you've got at the end and build some versatility into your car so you can run it just about anywhere on the track. This works really well for us.

[This message has been edited by AtomicPunk (edited February 12, 2005).]

Dirt Maniac

Total posts: 170
posted March 02, 2005 07:24 AM  
I am running a similar setup and have tried just about every cam out there on the dyno and found that mine liked the comp 12-250-3. its one of the extreme energy models they have.put out around 20 more ponies than anything i have tried yet. why ? dont know.
i know it has an awful agressive lift profile. i was running a crane saturday night special cam with good results but the comp has far exceeded it. i run a 355 with 10 to 1 comp. steel crank, powdered rods 5.7's, flat top pistons with 4valve reliefs.

Dirt Roller

Total posts: 23
posted March 11, 2005 06:28 PM  
To me you answered your oun question. You need more gear!! Think abought this.. you say worse when slick and you are unable to keep corner speed up. So if lap times slow down, you need more gear to stay in the power band. Kinda like lugging around the yard in high gear, someone in low gear will smoke you off the turn. hope this helps!!

Dirt Freak

Total posts: 466
posted March 11, 2005 06:38 PM  
I would say go with the 406 if you want to stay with your gear. You can lug a 406 more and make more power then a 350.

What class are you running?

[This message has been edited by BIGDADDYBOZ (edited March 12, 2005).]

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