[RDW]

So I want to make my car more drivable. i didn’t build the engine and I don’t know the specs but I will list what I do know. 327 bored 30 over 202 heads edelbrock intake Holley 600 . Also has HEI ignition. right before I bought the car the gentlemen took a tunnel ram and duel 4bbls off of it.
it has one hell of a lope to the cam and loves every gas station I pass.
Thanks in advance

 

[copo9560]

What is now installed? Solid? Hydraulic? Roller? What rockers are under covers - stamped or rollers?

To select a cam more information would be helpful. Performance goals, transmission, converter stall, rear gears and most importantly how will be car be used.

 

[FbodyMike]

In addition to the above, to pick the right camshaft, really need to have an idea of the compression ratio. If the builder raised the compression ratio and the new cam has the intake valve closing is too short , it could detonate badly.

It would be worth removing at least 1 head and measure the chamber volume and piston cc to calculate the static compression ratio.

Another second thing worth doing, would be getting a degree wheel, and reverse calculating the valve events to get an idea of the current cam that's in there now.

While you're at it, measure the total valve lift to give you an idea of what the springs can handle. Even if you go with a milder cam duration-wise, doesn't necessarily mean the previous one had more lift.

Also, does the HEI have ported vacuum advance connected?

 

[fairfax1000]

So I want to make my car more drivable. i didn’t build the engine and I don’t know the specs but I will list what I do know. 327 bored 30 over 202 heads edelbrock intake Holley 600 . Also has HEI ignition. right before I bought the car the gentlemen took a tunnel ram and duel 4bbls off of it.
it has one hell of a lope to the cam and loves every gas station I pass.
Thanks in advance

I would take a look at what GM offered on the 327/275 hp engine with a 4 bbl. If it worked for regular production cars, it will work for your goal.

 

[Melrose RS]

I would take a look at what GM offered on the 327/275 hp engine with a 4 bbl. If it worked for regular production cars, it will work for your goal.

Much too weak. Having started with that stock cam, going to 204/214 and now a Crane 272h10 i can tell you there’s no downside to going at least this big.

 

[RDW]

I have no idea what cam is it in now, I do know it’s a flat tappet. The car has a th350 with a 2800 stahl and 3.73. gears in the rear end. I just want to drive and enjoy the car. I’ma retired hvac tech and not a mechanic but I’m learning

 

[fairfax1000]

I have no idea what cam is it in now, I do know it’s a flat tappet. The car has a th350 with a 2800 stahl and 3.73. gears in the rear end. I just want to drive and enjoy the car. I’ma retired hvac tech and not a mechanic but I’m learning

Everyone will have opinion for your post. I do think moving to stock specifications will make the car more favorable to drive.

 

[FbodyMike]

Everyone will have opinion for your post. I do think moving to stock specifications will make the car more favorable to drive.

The previous owner made several modifications to the engine. What if he raised the compression to 11.5:1? The stock camshaft would be a disaster even running premium fuel and the timing dialed back.

 

[bilodeaulynn]

I see the PO succumbed to "More's Law". If some is good, more is better. Why won't it idle with the gigantor 909 cam?

Agree that you need to at least make some effort to see what compression you have. You can run a compression test. Yes, I realize that a radical cam will skew that result, but will give you a general idea.
You can also get a boroscope and look into a cylinder through the spark plug hole so see if the piston is flat or domed.
I have this one. Reasonably priced and works well. Has more features than my little pea brain will ever figure out: Amazon.com
I see it has been discounted to $107 with prime. I paid $150 less than a month ago.

"2.02 heads" are likely the small combustion chambers. They made a few in the 70s with larger chambers, but not that many. You can pull a valve cover and get the casting number. Post it.
If it has domed pistons, and you want a milder cam, you will EITHER need to swap heads for something with large combustion chambers, or go with flat tops. Either way, you are opening a can of worms.

If it has flat tops, you still won't know the exact compression ratio, but you could then roll the dice and swap to a milder camshaft. Still a bit of a crap shoot. Lots of good cams available. I really like hydraulic roller cams even for mild builds. No worries about wiping a lobe. I have used this Crane hydraulic roller in two engines (both 350 bored .020): 119811; although a quick check shows it to be out of stock right now. Very happy with the result. Super smooth idle. Great torque. Not designed to go over 5000 rpm. I got over 20mpg on the highway consistently in a 68 El Camino (not the most slippery design out there) with 3:31 gears and a 4L60E trans. I had flat tops, 186 heads (with the 1.94 / 1.50 valves). IIRC I had right about 10.25:1 compression ratio. HEI recurved. 8 degrees initial, 36 total, vac advance hooked up to manifold vac with a stock Qjet on a stock cast iron intake, both 68 vintage. I jetted the primaries down one size. Everything else in the carb was bone stock. Ran 91 octane and never had a ping. I could light up the 275 60 R15 rear tires at will. Tons of torque.

 

[slazisme]

Don't know if you're working on a budget or want to re-do things more thorough. You doing the work or a shop?

Flat tappet cam swap- with some new lifters, springs and pushrods. Streetable with what you have, less expensive but flat tappet cam can be dicey if lifters and lobes aren't checked.

https://www.summitracing.com/parts/sum-k1121/make/chevrolet

More options if you re-do heads and freshen things up, once you start then it branches out from there. e.g. roller cam, gearing, stall, aluminum heads.
Streetable possibilities are endless if you want to go that route.

 

[Larry Madsen]

You say, “it has a hell of a lope”.

That alone tells me that you need to know the static compression ratio.

If you install a milder cam you could easily drive the dynamic compression ratio to a very bad situation.

In an engine build the cam is the very first part you select. Not the last. 🤔

 

[FbodyMike]

I have used this Crane hydraulic roller in two engines (both 350 bored .020): 119811; although a quick check shows it to be out of stock right now.

Unfortunately Crane is out of business... again... probably permanently this time.

 

[bilodeaulynn]

Well that sucks. The two I used worked great, and did not require any special gear on the distributor. I did have to install a cam button on the front cover.

 

[bilodeaulynn]

What is the casting number on the heads you have right now?

 

[RDW]

What is the casting number on the heads you have right now?

The casting number is 8890462

 

[RDW]

8890462

 

[Lickity-Split]

All good answers, but for practical purposes you already have enough information to call Comp Cams. Ask for a cam suggestion, and they'll give you to a guy that can help you. It's what they do, and they like to do it.

 

[bilodeaulynn]

If you look closely, I think you will see that the first digit is a "3", not an "8". Really hard to tell sometimes.
3890462
Before calling anyone, I would at least determine if you have flat top pistons or domes.
Those heads were 64 cc (small) chamber heads from the factory. Unlikely they have been enlarged.
Cam company is going to want to know valve size and at least approximate compression.

 

[BillK]

Like the others have said you really need to have some idea what the compression ratio is. That will be critical in picking a camshaft. Can you get in touch with the previous owner and see if he has the information ? A bore scope would be best but you might be able to look in through a spark plug hole if you can get the piston up to TDC and see if it is a flat top or something else.

 

[RDW]

I have a friend bringing a bore scope over this week so I’ll be able to check