mikeyt

I've got a 92rs that I'm replacing the heads with Vortec heads. I've looked at Lt1 cams however the ones I've seen have a gear for the Optispark distributor and I don't have one. Does anyone know what year cam I need to have or a number. I'll be getting one from a machine shop that has them, just not sure what number or which one I need.

sofakingdom

iTrader: (1)

Optispark doesn't use a gear. It uses a long dowel pin on the front of the cam.

The distributor you have, DOES use a gear.

Get one of the Vette of F-body ones. (there are several of those) DON'T get a B-body one.

mikeyt

I know it does have a gear. I was reading something on it and it mentioned this so, I wasn't sure. Here's one I'm looking at on ebay, would this work well?

YOU ARE BIDDING ON A HYDRAULIC ROLLER CAMSHAFT THAT WILL FIT THE 1987 UP CHEVYS AND FIREBIRDS THAT HAVE THE HYDRAULIC ROLLER DESIGN. THESE CAMS ARE INSPECTED,CLEANED, STRAIGHTENED AND THEN GROUND TO THE SPECIFICATIONS OF

.495 INTAKE LIFT / DUR.@.050 .218 DEGREES

.502 EXHAUST LIFT / DUR. @.050 .224 DEGREES

LOBE SEPERATION IS II0 DEGREES 112 LOBE SEPERATION AVAILABLE UPON REQUEST

THIS CAM WORKS WITH THE STOCK TORQUE CONVERTER. IF APPLICATION IS FOR LT1/LT4 SPECIFY IF LONG DOWEL PIN IS NEEDED. CAM IS AVAILABLE WITHOUT FUEL PUMP LOBE. THIS CAM LIKES A STAGE ONE CHIP. VERY STREETABLE AND A GOOD ADDITION TO ANY LT1/LT4 POWER PLANT.

FOR OFF ROAD USE ONLY! there is NO GUARENTEE OF EMISSIONS COMPATABILITY.........THIS CAM HAS NO FUEL PUMP LOBE Call If You need the fuel pump lobe (aditional charge of $20.00)

1992-’95 350 WITH ALUMINUM HEADS - The 1992 Corvette had a steel roller cam with a shallow hole in the snout that measured .450" in the front and tapered down to .240" at the bottom. It had a short dowel (.320") that was used to locate the timing gear and a hole with 16 splines in the center of the gear for the stub shaft that drove the early distributor. The 1993-‘94 H.O. cam had a few subtle changes, but all of the early H.O. cams are the same for all intents and purposes. They can be identified by the number "241" stamped on the barrel in front of the first lobe.

bigal55

iTrader: (1)

As Sofa stated above, the only difference is the length of the dowel pin that locates the timing gear. The LT1 used a longer dowel that drove the optispark . You can not use a cam with the long dowel in regular sbc as the dowel will hit the timing cover. That being said, the dowel can be shortened or as the ad says, tell them you need the short dowel and no you don't need the fuel pump lobe. HTH!

mikeyt

By those numbers is that a good cam to use?

cardo0

I don't recognize that as any GM cam Mikey. For early roller blocks u can just knock out that dowel pin with a punch. But u need to find out whether your cam has the same nose - stepped or flat faced - as that cam. I believe the early roller blocks used a flat faced cam w/different retainer than the later stepped nose cam blocks. U can and should research this for yourself.

I think that cam should perform similar to the ZZ4 cam as the specs are close.

Good luck and let us know what u find out.

sofakingdom

iTrader: (1)

Looks like a stock cam that's been re-ground to the approximate specs of the Comp "502" grind except with the lobe centers changed. Real close anyway.

http://www.summitracing.com/parts/cca-08-502-8

A 305 with stock gears and converter is not enough motor for that cam. Especially not with the tight lobe centers; a 305 with a stock tune WILL NOT be happy with that thing's 110° lobe centers.

Stick with something about in this range. Next step down, and with a more EFI friendly lobe separation. It's about as big as you'll be able to stand. Although of course, a NEW cam, not a stock cam with its case-hardening ground off into a knockoff of somebody else's product.

http://www.summitracing.com/parts/cca-08-501-8

Thirdgen89GTA

iTrader: (5)

Why are you looking at LT1 cams if you don't have an LT1 engine/ Sure, they are like 99% compatible, you just need to tap the dowel in so its not too long.

But there isn't any reason that you can't look at off the shelf grinds for SBC Gen 1 rollers.

The LT1 grinds offer you nothing over a Gen 1 SBC cam.

86LG4Bird

iTrader: (1)

mikeyt, Is this for a 305 or for a 350?

mikeyt

This is for a 305, I'm sorry for not specifying earlier. Also, I was going with this one because of two things, I thought it was the right one and the price is right. I really don't have an extra $250 plus to spend on one. Now if you guys can give me lobe separation, lift and duration numbers, this guy will grind me a cam for the same money. So please let me know, thank you in advance. And yes buy the way I'm getting a chip for it, I just haven't given the cam specs to him for the tune. Oh, BTW do I have to take the condenser out to do it and discharge the Freon and go through all that to do it?

mikeyt

Hey Sofa, it looks to me if this guy would grind a cam to these numbers which are off the other cam, I'd be better off you think. With the lobe separation greater would I get more of lopy nature to it?


:Intake Duration at 050 inch Lift: 212
Exhaust Duration at 050 inch Lift: 218
Duration at 050 inch Lift: 212 int./218 exh.
Advertised Intake Duration: 264
Advertised Exhaust Duration: 269
Advertised Duration: 264 int./269 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.488 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.495 in.
Valve Lift with Factory Rocker Arm Ratio: 0.488 int./0.495 exh.
Lobe Separation (degrees): 112

mikeyt

I was looking at this cam due to the fact I am putting Vortec heads on it.

86LG4Bird

iTrader: (1)

I could make things easy and cheap for you.
A stock L31 Vortec cam...... $50 plus the ride and it's yours.
It won't lope, but will make some darn good power in a 305.
It's used, has the normal discoloration, but no detectable wear.
That cam made 255 to the wheels under a stock L31 intake, stock Vortec heads.
The same cam, retarded 5 degrees, made 309 to the wheels under an LT1 intake, and stock heads. If it can do that in 350 cube motors, you know it will flow enough for a healthy running 305.

sofakingdom

iTrader: (1)

No, exactly the reverse; the greater lobe separation will help fix the "lope" problem that you're trying to avoid.

"Lope" is caused by the int valve opening while there's still pressure in the cyl, and the spent gas in the cyl contaminating the incoming int charge for the next firing. It costs power, gas mileage, idle quality, and efficiency. Wider lode separation makes the exh open earlier, which gives the exh valve more time to let the cyl empty itself out.

If you think your 305 is gutless now, just put a cam in it with "lope", and leave the stock converter and gears in it. You'll get a whole new level of gutless. It'll feel like you took out at least 2 cylinders. That's a disappointment to be avoided: spend money and do work, just to slow your car down.

Why would you want a stock cam core with the case hardening ground off? Forget about "this guy" and buy a good quality cam, if you're going to buy a cam.

A cam is NOT a good place to try to cheeeeeeeeeeep out. It doesn't matter how little you think you have available to spend on it; it's NOT WORTH the compromises that a poor cam selection produces. Do it ONCE, get THE BEST thing you can for your setup, you'll be MUCH happier in the long run. The cost of the parts to build a motor just DISAPPEARS INTO THE NOISE LEVEL after about a week of driving the car: anything you did that WASN'T optimum, you'll HATE every time you turn the key. Life is too short for that.

No you don't have to discharge the AC. You can move the compressor and condenser together as a unit; just kinda rotate em up and over to the side out of the way.

mikeyt

Bird you are too funny. Sofa, I didn't know about this. I thought a reground cam is one that was used and cleaned up we'll say. So this is not reground, just ground off to make these specs?

mikeyt

So I want 112 degrees of separation, right? Also I've heard about lt4 cams are an option, what do you recommend for those?

mikeyt

Is one better than the other?

mikeyt

I see the lt4 has a .525 lift which would require new valve springs

86LG4Bird

iTrader: (1)

?? I don't know what you find funny.

Thirdgen89GTA

iTrader: (5)

Stop. Just. Full Stop.

Do not SKIMP on the cam. Its the brain.

Know your displacement. Know your head flow and runner sizes. Know the RPM range want the engine to run in.

Then based on that information, decide what duration, lift, and lobe separation the cam should have.

Don't pick a cam because you want Lope. Lope comes with overlap. Usually there is overlap because you are maximizing power on the top end while sacrificing low end grunt.

Do it right, or just run a stock cam and be done with it.

Not only do you not want to skimp on cam materials, you don't want to skip on the actual components that will drive your cam selection.

You can attack the question from many different angles, but ultimately all of the questions are the same, just answered in a different order.

You have a 305.
You have Vortec heads, and I assume a stock valve train.
You want a cam that will play nice with those.

This ultimately means that you will want a fairly low lift, and low duration cam. You won't have any overlap really. Which means its not going to be a high compression, choppy engine at idle. its going to be a smooth burble.

Wanting a Choppy idle, but not having the components to support high RPM power means you are sacrificing power, economy, and drivability for no gains.

mikeyt

Bird I meant $50 for the cam, then the drive to Indiana to get it

mikeyt

89gta, that's exactly what I'm looking for a smooth rumble, not potato-potato, something that's going to work with the heads I have and the stock bottom end. I'm going to spend the extra money, so I'm looking for the right one to pick that's all with so many choices out there. It's a daily driver so I'm looking at a Lt1 it sounds like, would that be correct with a lift approx.

Ty92Z

iTrader: (11)

The "ride" he was referring to was the shipping costs. The cost of the shipping or "ride" from him to you.

86LG4Bird

iTrader: (1)

Thank you

mikeyt

Ok I'm a dummy...I'll admit it. Gotta laugh at myself for that one, my bad

mikeyt

Hey guys, I found another one, tell me what you think

APPLICATION:




1995-1997 Chevrolet GM 350 5.7L OHV V8 LT-1

VIN "P"

1995-1997 Chevrolet Corvette

1995-1997 Chevrolet Camaro

1995-1997 Pontiac Firebird





THIS LISTING WILL INCLUDE:

•(1)ROLLER CAMSHAFT




Valve Lift (Int./Exh.): .447/.459

.050" Duration (Int./Exh.): 205/207

C/L Angle: 117

86LG4Bird

iTrader: (1)

THat's a stock LT1 cam, with a stupid-wide LSA that helps idle smoothness and emissions.
The one I offered you will have a better powerband in a 305.

mikeyt

Gotcha, I'm going to call to see if it's a miss print. But on yours do I have to retard the timing, can I run it just regular?

86LG4Bird

iTrader: (1)

In a 305, you would run it as-is.

mikeyt

What does a stock L32 cam come out of?

86LG4Bird

iTrader: (1)

You mean L31? It's from a 350 Vortec (L31 motor).
Same specs as the LT1 B cam which came in the Impala SS, 5.7 L Caprice, Roadmaster and Fleetwood, but with the traditional 5 degrees ground-in advance rather than the "straight-up" installed position as in the LT1's.

mikeyt

Got me on the type-o. Since it already has the advance built in your saying it can be4 installed in the normal position?

86LG4Bird

iTrader: (1)

Exactly.

mikeyt

So then are you saying a L31 cam is better than a Lt1, or is it better for what I'm doing?

sofakingdom

iTrader: (1)

Lobe separation and "cam advance" are 2 completely different things.

THIMK for a minute or 2 about basic 4-stroke engine operation. Let's imagine we start at the start of the intake stroke.

At that point, the piston is at TDC, and the intake valve is JUST BEGINNING to open.

The engine rotates some more. As the crank turns, so does the cam; only, the cam turns half as fast. However all that may be, as the engine turns, it's in the intake stroke; the piston is descending; and the int valve is opening. About halfway down, the int reaches FULL OPEN (we'll come back to that point shortly). The crank has turned 90° and the cam has turned 45°.

The engine rotates some more. The piston continues to descend and reaches the bottom. All this time since the halfway point, the int valve has been closing. As the piston gets to the bottom, the int is nearing full closed. The crank has turned 180° (half a turn) and the cam has turned 90°.

We just went all the way through the intake stroke and all the events that accompany it.

The engine continues to rotate. The valves are both closed, and the piston begins to ascend in the bore. Presently it reaches the top. Shortly before it reaches the top, a spark is delivered, igniting the air/fuel mixture that jus got intook. The # of crank degreed before the piston gets all the way to the top that this occurs at, is called "ignition advance". N00bz call it "timming". (sounds like something your mom would catch your brother Tim doing in the shower and would warn him about he'll go blind if he keeps that up...)

This was the compression stroke. The crank has now turned 360° (one full turn) since we started, and the cam 180°.

The fuel slowly burned starting when the spark occurred, and kept on burning for some time afterwards as the piston moved the rest of the way toward the top. Besides the pressure that was created during compression, the gases in the cyl are now SUPER pressurized because of the heat. The pressure in the cyl as the piston goes through TDC is something on the order of 1000 psi. This YUUUJJJJE force pushes the piston downward, which makes the crank rotate some more. This is the force that actually results in the production of useful mechanical power to push the car around. The crank continues to rotate until it reaches the bottom, all the while, delivering power toward the wheels. When the piston reaches the bottom, the crank will have turned 540° since we started (1½ turns) and the cam 270°, or ¾ turn.

This was the power stroke.

As the piston gets real close to the bottom, the exh valve begins to open. The cyl still has relatively high pressure (a few hundred psi most likely), because unfortunately, the engine is incapable of extracting ALL the heat energy and turning it into mechanical energy. As the exh valve opens, the pressure begins to drop rapidly. The crank continues to turn due to the inertia of the flywheel. As it turns, the piston passes through BDC and begins to ascend once more, and as it does so, the exh valve continues to open. Much like the intake, somewhere around halfway up, the exh valve reaches peak opening (more on that shortly as well) and as it continues farther the exh valve starts to close. As the piston gets to the top the exh valve approaches fully closed. We are now right back where we started: one full engine cycle for that cyl. The crank has now turned 720°, 2 full turns, and the cam 360°, 1 full turn. The int begins to open once more.

This last was, incredibly enough, named the exhaust stroke.

So... THIMK about the relationship between when the exh valve reached peak opening, and at some later point, the int reached full opening. Those 2 things happened some number of degrees of CAM rotation apart. If the exh was full open at exactly halfway through the exh stroke, and the int full open at exactly halfway through the int stroke, then they would be exactly 90° apart. The LOBE SEPARATION would be exactly 90°. This is ground into the camshaft and CANNOT be changed without changing the physical camshaft somehow.

In the real world, if you designed a cam exactly like that, it would make the motor run like a tractor. It would have MAXIUMUM low-end grunt, but would leave much to be desired at higher RPMs, because the gases in the intake manifold and exhaust system take time to get moving and time to stop. They have mass and therefore INERTIA. To improve the engine's high-RPM behavior at the expense of some of that low-end grunt, the int valve is opened a bit later and held open significantly into the power stroke; and the exh is opened earlier. IOW, the LOBE SEPARATION, the # of ° between peak exh opening and peak int opening, becomes greater than 90°. Typical cams for engines like ours have lobe separation anywhere from 108° to 117°.

Now consider what happens if you alter the timing chain somehow, such that the ENTIRE camshaft event sequence happens either sooner or later. The RELATIONSHIP between int and exh events does not change; they are both xxx° apart, as determined by the cam grind; BUT the int reaches peak opening at some OTHER number of CRANK ° beside 90° ATDC as the piston goes back down. In reality, most V8 cams are set up with the int lobe center somewhere around 104 - 108° ATDC. You the INSTALLER have control over this, via things like the crank key, cam bushings, etc.

Now that you understand CLEARLY how a camshaft works, it should be obvious what happens as you vary the different parameters. The longer the int & exh valves stay open, the longer the air has the chance to flow through them; BUT, at low RPMs, the more of it ESCAPES when it should either be getting compressed or should be doing work. Either of those 2 things reduces low-RPM torque.

At the same time, if the int valve begins to open before the pressure in the cyl has bled down through the exh valve, then EXHAUST gases from the cyl (which are under pressure) will flow BACKWARDS into the intake manifold (which has VACUUM, otherwise known as NEGATIVE PRESSURE) before the piston begins moving down and sucking on the intake. The incoming intake charge will be POISONED by this "reversion"; it is, QUITE LITERALLY, built-in exhaust gas recirculation aka EGR. This is what causes "lope". "Lope" is an indication that low-RPM performance is being sacrificed.

Note that this is NOT the same thing as "overlap". "Overlap" is, literally, the period of time that the int and exh valves are both open at the same time... their operation "overlaps". "Overlap" in and of itself DOES NOT cause "lope", or really, any other problem besides the possibility of intake charge being drawn all the way through the cyl and coming out the exhaust. However, it is a VERY CONVENIENT method of evaluating how "big" a cam is, given the conventional ways of designing them.

You have a 305. It is already challenged in every possible way with respect to power production: the valves are too small, they are too close to the bore, the stroke is too long compared to the bore for the overall design of the heads. It already suffers from a lack of torque. Furthermore, you have stock gears, which are 2.73 if original; they prevent the engine from EVER running at anything that could be classified as "high RPM" until the car is already above any legal speed limit. Your engine will NEVER see "high RPMs" except for when it's out of gear. To make matters worse, you have a stock torque converter, which "slips" (actually, multiplies torque by allowing the engine to rev up) whenever its INPUT (engine) side is below about 1600 RPM, but hooks up more or less whenever the OUTPUT side (transmission) is above 1600 RPM. This is what gives it the effect where you step on the gas, the engine goes to 1600 RPM, the car creeps off the line, then at some point maybe 30 mph or so, the engine RPM begins to climb. Bottom line, your engine will NEVER see any RPMs in actual operation, above 3500 or so, which is like 70 mph IN FIRST GEAR. It is POINTLESS to sacrifice power at the RPMs your engine will be spending 99.999% of its life in, to get power at some RPM it will NEVER EVER reach in any useful manner.

[fingers give a sigh of relief]

The Vortec cam is probably too little to be worthwhile. It is less cam than what you have now. The ebay stock F-body LT1 cam is still just a stock cam, but will let your engine breathe A LITTLE BIT better without killing off its low end. Kinda like all the kids I used to build motors for back in the 70s... they'd bring stock me a Nova 350 2-bbl or the like, that would spin the tires MERCILESSLY at a stop, but they couldn't pass a semi on a 2-lane road at 45 mph. They'd want a cam that has "lope". I'd protest and try to talk em out of it, but after the price went up enough, put em one in, and they'd bring me back the car complaining it wouldn't smoke the tires at a stop light anymore. Well, duhhhhhh... I tried to TELL you that, BEFORE you wasted your money.

The stock unmolested LT1 cam, NOT reground, is probably the best all-around compromise for your situation.

eseibel67

Sofa: Another Masterpiece of automotive education. I've been fixing cars and thinking about the Otto cycle for 35 years and this was a great refresher. Even without pictures I could see the valves moving. I will save this post for the next time I explain engines 101 to a teenage kid. Thanks.

Fast355

iTrader: (2)

I put a 1996 L30 305 Vortec from an Express that I re-ringed at 250K miles into a 1999 Tahoe that has the stock torque converter and 3.42 gears. I used a flat tappet Lunati High Efficiency 268 cam. I went with the flat tappet cam because I had it laying around and it kept me from having to change anything with the heads. Was easy to tune and it accelerates quicker than a stock Vortec 5.7 in the same truck. Has a really nice sounding idle as well. After tuning it really pulls hard in the 3,500-5,800 rpm range. Has good driveability and pulls the truck along just fine even down to 1,200 rpm in OD.

mikeyt

Sofa....I am AMAZED, period!! That was a lot to digest and I had to read it a few times to get every nuance, however-so well worth it, thank you. So the Lt1 cam needs to be my choice. That being said, these Vortec heads are stock heads that have the faces ground down 0.030" to make the cc chamber 58cc from the 64cc they normally are. I was told by the rep at Jegs I was talking to tonight that I couldn't go above 0.475" of lift without having to have either more valve work or changing springs. Without having to do either of those things can I still run a Lt1 cam that has between approx. 0.475" to roughly 0.495" of lift?

mikeyt

I found a melling pn22216 and a Chevy Performance Jegs pn 14097395, maybe either of those?

sofakingdom

iTrader: (1)

No.

As the valves open, the bottom of the retainer moves toward the top of the valve guide. At some point, if the valve moves enough, the one hits the other. Any idea what happens when 2 pieces of metal, one a moving part and one a casting, try to occupy the same volume by meeting head-on? It isn't pretty. SOMETHING has to give. Either a stud pulls out, or a rocker bends/breaks, or a push rod bends/breaks, or SOMETHING. Whatever is the weak link that fails, it's not good.

"LT1" doesn't make any difference. The clearance between the retainer and the valve guide is a property of THE HEADS and the parts installed in/on them. Vortec heads, the REAL ones anyway, not sure about the 305 ones, are well and widely known to only have something between .460" and .480" (production tolerances being VERY wide) of space in that spot. Which means, that's ALL the lift you can POSSIBLY use, without addressing that shortcoming, if your heads have it. I'd advise checking before tempting fate.

There are solutions however.

Not sure what the Melling cam is, beyond that it's a flat-tappet (not a roller-tappet), which automatically means you don't want it; the GM one is some lame sedan/truck kind of thing. Neither one is appropriate to the situation at hand.

86LG4Bird

iTrader: (1)

With typical street gearing/TC, the L31 (LT1 B-cam) will be quicker in your 305 than the F/Y LT1 cam will be. The F/Y LT1 cam will have a higher peak, but a weaker curve in low/mid rpm's. That is exactly why GM put the B-cam in the heavier LT1 (350 ci) B-body cars.
Lope (or rather lack of lope) will be exactly the same. The overlap area of those two cams is identical.


Sofa, you got the theory down, but a little short on actual experience this time. You couldn't be more wrong about the Vortec cam. Put its published duration numbers aside and try it sometime. It's gone 12.3's in a 4000 lb vehicle No way in hell the F/Y LT1 cam is going to beat it in a street weight/geared/TC, low-compression-305 that the OP is dealing with.
Less cam than he has now? Hmmm... what's in a 305 in a '92 RS?

mikeyt

I just talked to Chevy Performance tech line today about this. They told me that this pn14097395 is between the performance of a L31 and a Lt1. It is put is 383 stroker motors that are daily drivers to get a balance between some of the top end power of the Lt1 and a good low to mid power band, along with a not too aggressive idle.

86LG4Bird

iTrader: (1)

Yes, that's the Ramjet cam, and if you want to buy new, it's the best cam for your application of all the cams that have been mentioned in this thread. I don't know exactly how much it would give you over the L31 cam in a 305, but yes, definitely a slight edge. I just thought you were on a tight budget since you were considering re-grinds; that's why I offered you the bargain option earlier.

mikeyt

Oh yes I do have a tight budget, however on internal parts that I have to do one time, I figure I need to spend the extra. The reason I looked at the regrind was because of the price,I really thought one of those would be ok, however thanks to you guys I know better. I bought the GM Performance cam and a brake vacuum canister just to make sure I would have enough vacuum at low rpm levels so I wouldn't get brake fade. If I don't need it I'll send it back. I have to remind myself that this car is my 17yr old daughters' first car and it's a daily driver. All this to say thanks for the great education I've gotten.

mikeyt

I do appreciate the offer of the used one and if it were my car I may do so, however if for some reason there was mechanical problem I wouldn't want to hear it from my wife....HAHA

sootie007

I ran the 395 ramjet cam in my 91 L03 with stock 91 TBI heads last year for about 3 months ....after ALL the work it wasnt really worth it i.m.o if your looking for a noticeable jump in hp its just not going to be there with that cam . The cam idles "very" smooth and has plenty of vacuum - you wont need that vacuum canister. Here it is running ....

sootie007

Smooth as silk you can only hear the fan running......

cardo0

Well Mikey i have to say that B-body cam is a much better idea than a stock LT1 cam. It really matches your 305" displacement well using Vortec heads for a daily driver. It should make great torque and have that smooth idle u asked for.
Im running the Ram Jet 350 cam in my LT1 350" and its OK but im still tuning it as it gained over 20hp on the first tune. It has 18.5" of vacuum but became a real gas hog w/18mpg. I think that B-body cam will have great vacuum to and u can find them used. Those early roller cams were billet metal stock and a used boneyard cam should still be good to use. My Ram Jet 350 cam cost like $220 but i cant find'm used like the B-body cam. I suggest installing it with 1.6 ratio rockers on the intake valves only for a little added torque. And i dont expect u need much tuning for that B-body cam. If your looking for bang for the buck that B-body would be hard to beat for value. Any quality performance roller cam is gonna be over 300 bucks and unlikely a billet core.

Thx to sootie for sharing.

86LG4Bird

iTrader: (1)

Yeah, you can send that vacuum canister back. No need for that with any of the cams being discussed here.
A used roller cam is no risk whatsoever if the lobes, journals, and dist. gear pass a good visual inspection. And yes, cardo0 is right.....any GM cam is going to be ground on a higher quality/durability core than the cast cores from Comp Cams.

sootie007

Bird is right...I would have sold you my genuine GMPP ramjet camshaft for $50 plus shipping ......I only put about 300 miles on it .