I am currentley building a 406 sbc for my camaro-Have shortblock done has flattops and stock crank and rods arp . I just bought aset of heads and can't find any info on them-There world products sportsmans supposedley 64 cc angl plug 202 160 with 200 intake runners! I bought them from a machine shop ready! Sorry for the long post-AM NEW HEAR MY 1st post! Im don't spell well so bear with me! My car has 456 gears and turbo 350-3200 stall-I need a good proven solid cam-looking at midwest cams-Would like to run 11.50 1/4 turning no more than 6200 rpm's! Thanks if anyone can help! Like this sight! :)

I went with an Isky solid Z30 on a 383 with similar heads and pistons as yours, and it definately wanted more cam! It was advertised as having a "lopey" idle, but it was very smooth. I was dissapointed in the idle quality. So your 406 is going to want a lot more cam.

heres what i use elgin 556 533 lift 264 256 at ,050 i run neally the same combo as you are and you see what my chevelle ran with that set up.they make it in a small base circle also .i shift at 6200 and go thru the traps at about 6500.i always got mine from compition products .there are alot of manurfacturer that make the very same cam.ive also put a elgin 525 lift 250 duration at .050 in my brothers car it worked pretty well in his with a 406 in a street car with 411s and a turbo.i also changed to a solid roller 615 lift at 260 dur, and didnt pick up one bit in the 1/8th mile from the elgin .it did lighten my bill fold a little though

im not sure what size tire you are running but if its a 28or 26 inch you will be turning more than 6200 with 456 gears in the 1/4 mile.

Plan on running race fuel -- your compression ratio will be approx 11.5:1 with 64cc heads and flat tops in a 406.

With a 3200 converter I would look for a cam with 240/248* duration @ .050 on a 110* lobe separation. That should make a power band of about 2500 - 6200 RPM.

Your cylinder pressure will be high so detonation could be an issue if you don't run 110 octane.

You should be able to run mid - 11's no sweat if the car will hook up.

Crane Soild Cams PN#111431 F-260 260/268 @.050 .554/.574 106 LC

If lift is a problem then then try the Chevy 1st design Off Road cam listed in Crane's catolog as a Muscle car cam

Crane Solid Cams PN#968821 Off Road 257/269 @.050 .493/.512 112 LC
works good with nitrous.

Other choices that work good-
Isky PN#201070 Z-70 264/264 @.050 .548/.548 108 LC
Isky PN#201065 Z-65 272/272 @.050 .560/.560 108 LC works with nitrous

How about this camshaft- 252-256 at 50 deg. 542-553 lift- lobe separation 102-Also running 10.5X28 slicks-have access to Super vic intake and RPM-Should I change the 456 gears to 373's? Iam thinking the 456's are too much!

with a 3200 stall and <6200 RPM redline you need to keep the cam down in the 240's @ .050 with the wider LSA IMO

Hate to say it, but this combo is mismatched a bit -- either get a looser converter and put a cam in to spin it more, or find a way to get the compression down.

Just my opinion.

How about this camshaft- 252-256 at 50 deg. 542-553 lift- lobe separation 102-Also running 10.5X28 slicks-have access to Super vic intake and RPM-Should I change the 456 gears to 373's? Iam thinking the 456's are too much!

I would go bigger on the cam to @ 260-270 and have the lobe seperation between 106-110 and use the Super Victor and keep the 4:56 if you drag it alot, or run the cam you listed (252-256 but with a 110 lobe center) with the 3:73 and the RPM manifold if you drive it alot on the street

I would make some changes if at all possible. The biggest issue is that the compression and rear gearing are just screaming for a big ol bumpstick.....but the heads and the coverter dont agree....plus your rev limit doesnt fall in line with anything much bigger than low 240 duration at .050. If you put in a gaint camshaft, you cant expect those heads to keep up without work......and even if they were perfectly capable of keeping up to anything you throw at them....you cant expect to make the big power with a big cam if your gonna cut it off at 6200rpm cause of course, a huge cam will want to spin and make power at higher rpm. I was figuring on around a mid 240 degree cam at best to compliment the heads.

As far as the cam, the lunati 401A6 looks good. Its numbers are 243/251 at .050, .518/.530 lift and a 110LSA. There are others that fit the bill but I wouldnt be going any bigger unless your ready to spin higher to make power cause a bigger cam will need to. This one will like to rev enough itself. As is, any headwork you can muster up will help your cause a LOT....and the bigger the cam, the more this really becomes something that should be done.

With that cam, the compression will still be a bit much. Dont expect to run pump gas unless this turns out to be one of those happy accidents that does somehow(happens sometimes) but the numbers dont say so. I figure if you arent going to make any other changes, youve gotta compromise somewhere and it would be better to have a little too much compression and have to put some real fuel in her than to have too much cam and not be able to spin nearly high enough to allow the big cam to make power.

Unfortunately, I just dont think a motor like this would have 11.50's in it. But, I also dont think putting in a bigger cam will save it. Youd need to make other changes. If you are willing to do so, get some good cylinder head work done. Thats a premium. Step up the converter to something more like a 3500-3800 converter and a cam of around 248/258 at .050 and a 108-110LSA could do it with the gears and compression. However, youd have to deal with the fact that it will want to run 6500 plus rpm.

406 combo was 10.17:1 TRW dished pistons,CC280H Cam (.486I/E 110LSA)Torker intake,72cc Protopline Iron Lightnings with 2.05/1.6 valves,th350 ,12" 2200stall,3.73 gears 27.5" tall McCreary's and ran a best of 12.5@110.

I went to a Vic Jr. and 10" 3000 stall - went to track and had traction issues (never hooked) but program shows 11.9X's.

I just bought a CC305H (.525 I/E) and program claims mid-low 11's.

But I have to tune what I'm running before the cam swap, too many changes at one time and got lost.

I'm going with the Isky Z-35 for my 383. I've heard that it sounds awesome and runs better than it sounds. I'm planning on a high winder too with 4.56 gear.

I would make some changes if at all possible. The biggest issue is that the compression and rear gearing are just screaming for a big ol bumpstick.....but the heads and the coverter dont agree....plus your rev limit doesnt fall in line with anything much bigger than low 240 duration at .050. If you put in a gaint camshaft, you cant expect those heads to keep up without work......and even if they were perfectly capable of keeping up to anything you throw at them....you cant expect to make the big power with a big cam if your gonna cut it off at 6200rpm cause of course, a huge cam will want to spin and make power at higher rpm. I was figuring on around a mid 240 degree cam at best to compliment the heads.

As far as the cam, the lunati 401A6 looks good. Its numbers are 243/251 at .050, .518/.530 lift and a 110LSA. There are others that fit the bill but I wouldnt be going any bigger unless your ready to spin higher to make power cause a bigger cam will need to. This one will like to rev enough itself. As is, any headwork you can muster up will help your cause a LOT....and the bigger the cam, the more this really becomes something that should be done.

With that cam, the compression will still be a bit much. Dont expect to run pump gas unless this turns out to be one of those happy accidents that does somehow(happens sometimes) but the numbers dont say so. I figure if you arent going to make any other changes, youve gotta compromise somewhere and it would be better to have a little too much compression and have to put some real fuel in her than to have too much cam and not be able to spin nearly high enough to allow the big cam to make power.

Unfortunately, I just dont think a motor like this would have 11.50's in it. But, I also dont think putting in a bigger cam will save it. Youd need to make other changes. If you are willing to do so, get some good cylinder head work done. Thats a premium. Step up the converter to something more like a 3500-3800 converter and a cam of around 248/258 at .050 and a 108-110LSA could do it with the gears and compression. However, youd have to deal with the fact that it will want to run 6500 plus rpm.

Well said Greg -- I agree 100%

And with the SpII heads, work on the exhaust ports will help a lot. I hear that those heads respond well to unshrouding the exhaust valve in the chamber which would also help reduce your compression ratio a hair.

76 the max gear for the 1/4 mile with your rpm limit would be 411s i would think but the 373 would be alot better than the 456 unless you are gonna run the 1/8th mile.make sure no matter what cam you go with that the valve springs will take the lift of the cam with out coil bind.your next step if your gonna just race it would be the coverter

Funny someone mentioned the 305 comp hyd cam-I actually have one on the shelf-My springs have 140 lbs though that are set up for solid in about 550-560 lift-might wipe a hyd out! So many different opinions on cams and I understand why weight converter gears etc> Interesting replies though-definetley a good subject and I appreciate the input so far!

76 Camaro

Welcome to the site man! Where in Alabama are you from? I'm glad you like the site.... I know IM HOOKED!

You will hear many sides to the coin here, but remember, it's all in what you take and apply to your own thoughts, likes, and dislikes that really matter. Myself, I find just about every morsel of information good. There are some SERIOUS guru's here, no matter how humble they appear to be.

There is nothing wrong with the comp cam 305. It would make a nice fence mender i'm sure! (Just kidding) But as some have suggested, I would go another route. (as the items you mentioned now will run... but not as good as it CAN run with a few tweaks in the combo)

I would recommend getting something a bit more oriented to what you have in your current inventory of parts, combo, etc now. It would also be in your best interest to get a maching set of springs for the cam that you choose. I would also look into gettign some port/polish/chamber work on those heads. 75% of the heads out the box need attention in some form or another.

By the way, you mentioned that you just got them back from the shop (machine?) What work did they perform?

If you are going to keep those heads, DEFINITELY get them worked. Like Eric said, the exhaust profiles are on the weak side, but they are a decent unit. I would start there because they are the key ingredient to ANY combination you put together.

If you would like the number to a good head shop, let me know.

Imho, don't use the 305 Magnum, use a solid instead!!

And I bet a 3.90 gear would be great if one is available? otherwise drop back to 3.73's and a smaller cam and let grunt move you... And tire to hook her too...

plus, I like the Z-35 too, even if I have never ran it..

pdq67

PS., I do hope you have a forged crank in your 400 motor if you are going to rpm it like the cams some of the guys have mentioned will go up to..

I agree with the 3.90 gear its a great street gear and 3.73s are a good alternative. The Z35 is a great choice also. I dont agree that the 400 sbc needs a forged crank. 400 cranks are very tough. I have raced stock 400 cranks for years up to 6500rpm. With proper machine work, balancing, and 11.1 or less compression it should live just fine. I wouldnt go shootin juice to it though. I would be more concerned with the stock rods ... thats scary especially if a heavy piston is used. All things considered that should be a really responsive motor with a little tweaking on the heads and a cam similar to the Z35 range. One thing to remember when you read about cam applications is they are referenced against a 350ci engine almost 100% of the time. So when you consider it for a 50ci larger engine it tames it down noticably.

I was just thinking about the Z-35 going up to say 7,500 rpm is all!

pdq67

FYI...Here are the specs for the Isky Z-35 in case folks were wondering:


Grind No./Type

Z-35 SOLID High performance. Street/strip. Lopey idle.

2800 Stall.

411-488 axle ratio.

Up to 750 CFM Carb. 10.5:1 compr.

RPM-Range -
3000-7500

Valve Lift -
INT .525
EXT .525

Valve Lash Hot -
INT.016
EXT .016

ADV Duration -
INT 288°
EXT 288°

.050 Duration -
INT 254°
EXT 254°

Lobe Center
108°

I was just thinking about the Z-35 going up to say 7,500 rpm is all!

pdq67

Yeah thats why I was saying they are rated on a 350ci engine. I would still say it would pull to 7000 or so. My thing is with those heads and depending on intake/carb combination peak power might not be but 65-6800. Also in many cases the last 500rpm your not going to gain a huge amount of power. So just set your shift point to a safe 6500 and run it. You wont be giving up a tenth on the track more than likely and your still as fast have the nice sound and if you want the power its there for those emergency close calls. :D At your own risk that is. We all risk it just have to decide how much you want to try. I have seen $20000.00 engines have problems its just the nature of the beast we love.

there are alot of people who think that because a cam is rated for 7000 rpms or better that they have to rev it to that to get all its worth but some times you have to use your head and let that thought go .the cam i was talking about was rated from 3000 to 7200 thats the 556 533 264 256 at 106 but i found out it didnt run any better by reving it higher than 6200 it was probable the heads that were restrickting it and they are sportsmen heads .myself i woundnt push a 400 past 6500 anyways but thats just me.we were running a 7.00 heads up one time and my buddy ask me how to slow his car up and i told him to cut back on the rpms .he was shifting at 7200 i think any ways he brought it back to 6500 and he ran faster .the moral of the story is that more is not always better..a 400 is not a rpm motor so be smart and race a other day

With a stock crank and rods I can see why he is wanting to keep it down to 6200. The Z-35 will take him a bit past that ;) In addition, his heads will make the power curve go flat on his 400 at about 6000 RPM so running it to "near 7000" won't have him going any faster

It just won't pay to rev this motor so why stick a big cam in it? I think the gears and CR are what are making you guys want to put the big stick in it . . . ;)

Eric is kinda hitting the nail b/c, that is why I always say to under-cam and build, gear and tire for midrange AND for higher rpm usage, upper midrange grunt!!

Unless you want to wrap h-ll outta her, and in that case, IMHO, build a great big bore, short stroke motor like a 302 or whatever trip's your trigger!!

AND then run her like you stole it!! You know, onna those, "Well, when in the h-ll are you gonna shift her?" motors!!

pdq67