My L82 short block should be finished.in the next couple of weeks. I am hoping it will only require a light hone so I can reuse the forged pistons. I have discussed cams with the machine shop but would like to get some more advice. I am running a 4 speed with the 370 gears in the back. I would like to increase the Hp and Touque but nothing radical, something with good mid-range torque with a little lope.
Also, can I stay with the original type rockers, or will I need to upgrade if so, do I need to go to tall valve covers and if so, will they clear the power booster? I plan to scrap the 882 heads and go with a set from Edelbrock or maybe AFR. (64cc, 185 intake) with the 02 valves. I am also running custom cast iron exhaust manifolds with 21/2" outlets and 21/2" pipes all the way out to MF's. Also have Edelbrock. Performer intake with the AVS 2 Carb.

 

cams determine where and what type power you want.
since you have a man trans more options are available.

basically, C/R and when you want power are big elements in cam selection.
meaning, either low rpm torque that falls on its face at high rpms or mid rpm torque that comes alive at higher rpms.

as far as rockers, besides ratio, 1.5, 1.6, some do require tall covers.
usually full rollers.

its a tough call picking a cam, the more you factor in what you want, the easier it is.

good luck

 

I have a similar engine, 10:1 compression, promax aluminum heads, and I picked the Howard's Rattler Hydraulic Roller. Power where I wanted it, and I wanted a rowdy cam!

525 / .530, Duration @ .050: 227 / 235, Centerline: 103, Rattler, Choppy idle, High performance street

 

What is your budget?

Jebby

 

I have the same engine mods, trans and rear end. I went with a Lunati Voodoo retro roller 282/290. I'm very happy with it. Good low end and slightly lopey idle.

https://www.lunatipower.com/voodoo-r...k-282-290.html

 

Melling 22000 327/350 HP will work fine. Thats' what we are gonna go with for my son's 74 L82 corvette. It will have a performer intake with the QJET. We are putting LT1 valve springs which will take .500 lift. Also new lifters and pushrods. Heads are the same 882s. Those will work for him just fine. Also, we are gonna use stamped roller tip rockers which will fit under the valve covers. Less lift but more duration.


Exhaust Duration at 050 inch Lift:
223
Duration at 050 inch Lift:
223 int./223 exh.
Advertised Intake Duration:
290
Advertised Exhaust Duration:
290
Advertised Duration:
290 int./290 exh.
Intake Valve Lift with Factory Rocker Arm Ratio:
0.447 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio:
0.447 in.
Valve Lift with Factory Rocker Arm Ratio:
0.447 int./0.447 exh.

Lobe Separation (degrees):
114

Stock:
Hydraulic flat tappet
.450 / .460 lift
222/222 duration
114 Lobe Separation Angle

 

In the interest of being succinct -Very high level response here....

I have a freshly machined spare 3970010 SBC block (bored .040 over) that I'll be chipping away at and most will likely scoff at me, but my cam of choice is the 280H. Just an amazing camshaft with gobs of low and midrange, which is where you want to be for a good street performer SBC. Of course you do have to worry about sufficient ZDDP levels by using either the appropriate oil or ZDDP additives as you would any other flat tappet.

I've got 1.6 ratio Scorpion roller rockers that I'll throw in too, and breathing/exhausting through a set of Blueprint H8002K heads, RPM Air Gap intake, and carb not yet decided on... I'm putting in a nice new BPE 396 into my '69 and am in no rush to assemble the shortblock.

I'd say 230 lift/duration (@ .50) is about as far as you want to go with (flat tappet) cam without getting too wild and un-streetable. I ran a 284-12 in the motor before and it was too much - too lopey and not terribly streetable, with most power coming on line in the upper-mid to upper range. Will never run that much lift/duration again in a 355 or similar displacement 10-10.5:1 street motor.

Just my opinion, so take it as you will, but the 280H is just about the most perfect grind you can get in a flat tappet street motor in the 400-450 HP @5500-6000 RPM range.

https://www.summitracing.com/parts/cca-cl12-212-2

If you don't want to worry about ZDDP levels and such, then go with a roller cam. They are pricey compared to the flat tappets, but there are a bunch of good options out there.

 

Cams are not a mystery. If you know what you previously had or have and how it ran. Then you have to decide what direction to go. Stay away from any factory or old style cams. They were designed in the 60 and 70's with very poor springs from that era. Oil splash cups, heavy rotators, and retainers. That is why all those motors had such low lift and very mild ramp rates. Modern lobe designs and springs make so much more performance even with the same .050 duration numbers.

3896962 Hyd. - 222/222 - .450/.460 - 114 - 350 L-46, L-82

So your cam is low lift and 222@ .050. People that go with less than 222/222 and think that they are making a hot rod are very clueless as to how things work. The 114 number is very important as to how the cam acts. 114 creates more vacuum and smoother idle along with high MPG. Modern LS motors are all 114 - 118 LC and use very high flowing heads to create power and efficiency. I followed this same pattern on my first 383. big 227cc heads and 112 LC.

Way back when I had an L-82 in my 79 I installed a H-flat Crane cam with 226/232 114 .514/.532 lift with 64 cc heads and two valve relief flat tops. It was a wonderful 355 ci with headers and true duals non emission. So you can see that it had only 4 more degrees of intake duration. wide 114 and lots more lift using 1.6 roller tipped rockers. It was a 20+ mpg on long road trips. I drove across the US several times for 5000+ miles round trips.

Static compression dictates maximum and minimum duration using Dynamic Compression Ratio online calculators.

 

the rockers you can go with are determined by the diameter of the spring and cap you run. Either investigate wha the heads may have or wait until they show up and then measure them and buy the rockers to fit our need. With all the changes I have done over the years there is no reason to go with the1.5 rockers when 1.6 are the same cost and give you more power. As for roller versus stamped, until you get into large lift with heavy springs yo wont see any real benefit. If you want to stay with stock covers you can by spacers. Once the heads are installed you can shim the rocker cover you have to fit over the rockers and see if they will fit behind your booster. They should, I ever ran into any issues with a small blok and a booster. If they fit then jsut buy the appropriate thickness valve cover spacer. they make aluminum and or extra thick gasket style

most sights will tell you the RPM range the cam makes power...anything below 2500 or 3000 is a waste, your idling up to 1500 and the main jets arent even in your circuit until above 2000. I would get the heads, figure out the compression ratio you will and call teh cam manufacturer