406 Cam opinions wanted....
 

I'm taking my 73's 406 to the shop in the next week sometime for rebuild. Unlike the previous owner who ran the car at the strip, I will mostly be using it on the street. It will see little if any time at the track. I've contacted Crane, Comp and Lunati for help with choosing a cam. I would appreciate opinions/feedback on the three cams they recommended. Here's my combo and their recommendations. Thanks.

406 small block (1970 400 +.030)
9.5 comp ratio
Speed Pro L2489F30 flat top pistons
993 75cc heads (ported with 2.02/1.60 valves, screw-in studs…I know, get a set of AFR's)
Crane Roller Rockers
Edelbrock RPM Airgap 7501 Intake
Holley DP 800 CFM #4780-2
MSD 8572 HEI tach drive & 6AL ign. box
Hooker Comp. Headers, 2 ½” exhaust into Magnaflow mufflers
Super T-10 trans.
3.70 rearend


Crane Cams No. 113532
Grind Number: Z-274-2
Basic Operating RPM Range: 2,200-6,400
Duration at 050 inch Lift: 224 int./230 exh.
Advertised Duration: 274 int./280 exh.
Valve Lift with Factory Rocker Arm Ratio: 0.473 int./0.486 exh. lift
Lobe Separation (degrees): 110

Lunati No. 60103
Basic Operating RPM Range: 1,800-6,200
Duration at 050 inch Lift: 227 int./233 exh.
Advertised Duration: 268 int./276 exh.
Valve Lift with Factory Rocker Arm Ratio: 0.489 int./0.504 exh. lift
Lobe Separation (degrees): 110

COMP Cams No. 12-250-3
Grind Number: CS XE284H-10
Basic Operating RPM Range: 2,300-6,500
Duration at 050 inch Lift: 240 int./246 exh.
Advertised Duration: 284 int./296 exh.
Valve Lift with Factory Rocker Arm Ratio: 0.507 int./0.510 exh. lift
Lobe Separation (degrees): 110

Given your intended usage, I think the Comp is too big.
Both of the other two would work well IMO.

Given your self-imposed limitation on heads I'd say either of the first 2 cams would be a good fit & make your motor a torque monster. I wouldn't expect to make much power at the top of the RPM range listed because your extra cubes will make those cams milder than they would be for a smaller inch smallblock.

If you want to make things more intense step up to good aluminum heads & pick the Comp cam or something with a bit less duration than it has to keep it street friendly. Good luck. :cheers:

The lunati 60103 would be the best choice, along with some better heads.

Put a OEM GM camshaft #151 in and enjoy the ride. :thumbs:

I think the comp cam is too big for a street application. The other two seem much more appropriate for the street. I would consider, if I was you, a retro-fit roller cam. The oil companys have removed some of the special additives (zink) in the oil you can buy today, and you could end up replacing a flat tappet cam sooner than you think. Diesel oils still have the additives in them, but in time they will go as well.

I chose the Comp cams xr276hr-10 224/230 @50 .502/.510 lift for my 406, but I hav'nt fired her up yet........ so I have no feedback for you. You could consider some vortec heads, there cheap, and great heads for the street.

I doubt you'd choose a Comp XE cam if you did any research on the these sites. There are way too many reports of wiped lobes. Yeah, the oil recipes have changed, but I contend the XE lobes are simply too aggressive. And if you wipe a lobe, it's a do-over.

But instead of worrying about which cam,..you're leaving 50-100 HP on the table by using those smogger heads. Any chance you can scrape up the cabbage for some aftermarket heads? If not, maybe your local machine shop (or speed shop) has a set of used aftermarket heads they'd rework for you and you could save a buck or two. And with a 406, go big, at least 215cc. It's hard to find heads for a SB-400 that are too big.

Good lucK!

You don't have enough compression to support the 240 at .050
Comp Cam.

Many thanks for the replies. I've been leaning toward the Lunati. I know the heads are the weak link in my build. Doing a complete frame off and I was hoping to reuse the 993's to save a few bucks. I was thinking about a a set of Vortec heads. But, figured they were a little small for a 400. The shop doing the machine work mentioned that I could go with a set of RHS heads for a decent price....will find out more on them when I'm there tomorrow. Can you guys recommend a set of heads that won't break the bank? Something other than a set of AFR's for $1500?

Go with the Iron Eagle Platinum 200cc heads with 64cc chambers.

Brodix IK200 http://store.summitracing.com/partde...5&autoview=sku