I’ve searched the site but found no definitive answer to these questions:

In the end I will keep all my smog / emission equipment, intake and Q-jet that was just remanufactured. I will keep stock look and be compliant with emission laws, which seems to be getting tougher here in NC. I’ve heard these heads crack and I’m not against replacing them but again “going with stock look and wanting to keep stock intake.

1) Has anyone reworked / replaced their heads (1981/1982) for more performance in which stock valve covers were still used?

2) Which heads, pushrods, valve springs and rockers were used?

3) What cam /lifters were picked?

I know the typical questions: What are you willing to spend and what do you want out of the engine.

I want a stock look with about 150 more horse power which focuses on reliability and quality. Engine has 68,000 well documented miles and I don’t believe the lower end needs any work.

Thanks for any help given.

Reefdiver

 

The stock valve covers will fit any small block heads from the very early '60's up through around 1986 so that is not a problem.

Here is an old school approach that seems to work pretty good: There are better heads than the ones on your '81 to pick from. You can use factory performance heads from the late '60's into the early 70's and pick up some compression and flow if you choose to keep a factory head. Ones from the late 70's into the '80's were a thinner casting and are prone to crack under the right circumstances. Either choose heads that already have hardened exhaust valve seats (due to the lead-free gas we use now) or have them installed when you get the heads reworked before installing.

It would take a trained eye to see the difference between the old and newer heads. The newer, thinner ones have a scalloped edge where the heads bolts go under the exhaust mounting face. The better ones have a straighter edge with small single scallops right under the sending unit location.

Make sure you choose ones with the mounting bosses and drilled holes in the ends for your accessory brackets (alternator, A/C specifically). Springs, pushrods, and rockers are common across many years of small block engines and unless you choose a radical cam they will work fine.

For factory engines, the old 350 horsepower 327 cam (or its equivalent) worked good on the street and had a good sound plus it works good with your stock intake and carb. I ran that cam in several engines and really liked the sound and performance without sounding like a race car. There are numerous aftermarket cams out there but you don't need much more timing that an early factory HP cam. Get new lifters for it or any other cam you choose along with a new timing chain and gear set. I always buy a steel gear set for a 1970 model 350 to avoid any strange emission-related cam timing settings.

Have a performance curve put in your distributor and add true dual exhaust if you can. Your goal is well within reach.

 

if you are going to keep the stock look and intake and everything, I would just get a set of Edelbrock performer heads. I believe they are 50 state legal and all your emissions stuff will work with them. you can paint them GM corporate blue to match your engine and no one will know the difference.

just get a cam that will work with your CCC

 

Those are a good choice, but I personally can't spend that kind of bucks on heads (around $500 each bare) when there are plenty of good factory heads floating around at reasonable prices. I bought a good set of ready to run early '70's L-82 heads for $100 and port-matched them myself for my street cruiser. With the pistons I installed in my short block I am running about 10.5 to 1 compression with 76cc chambers which is plenty for the street. I know I could be making more horsepower but I rarely need much more than I already have. It is all in what you want and can afford. Like they say. "Speed costs, How fast do you want to go?"

 

If you want 150 more hp Id pull the motor set it aside and build something larger with a good set of heads intake hyd roller cam
easy to make it all look stock still short of headers

 

Another good idea here. I tend to think within my own budget, which is a little slim at the moment. If you are bucks-up, then a new motor is the ticket!

 

To make a serious difference in power choose aftermarket heads with a modern design fast burn combustion chamber and go with a good retrofit hydraulic roller cam.

 

 

With a Comp Retro Roller K-Kit, you will have all new cylinder head parts (except valves) included. Therefore, if it were me, I would find a pair of rebuildable OEM or aftermarket heads for a good price (your local engine builder, ebay or Craigslist) with the 2.02/1.60 valves and guide plates installed. The K-Kit will include matched pushrods, dual springs, keepers, locks, seals, cam, lifters, timing set, button.

From my research, the Comp Retro Roller K-Kit has many advantages including:
You can use the stock distributor gear given the cam has the iron gear
You can use the stock timing cover (just shave the nylon button that comes with the kit so it just skims the inside surface of the timing cover... takes a few fitment checks to be perfect).
You may need a new fuel pump pushrod

I bought my K-kit from Atlantic Speed and saved $$$ off the Summit price for same. My kit had the same duration but more lift than my Crane Energizer 272-H10 grind which is very similar to the 350/350 cam but with shorter duration and tighter lobe separation. So, I didn't have a lot of tuning to make it work (oh, and I already had the DART Iron Eagles on my engine... just rebuilt them with the new parts). And, I get more, longer lift (power). I added a set of Comp Ultra Pro Magnum 1.52 roller rockers. I wanted a trick set of rockers as I've always had the Summit stamped steel with questionable ratio.

A few items to also replace:
New harmonic damper
ARP intake, head and timing cover bolts
Engine mounts
Fel-Pro top end gasket set

A few tools I purchased:
damper puller
damper installer
crank gear puller
crank gear installer

The K-Kit runs about $950. Add:
Cylinder heads purchase/rebuild with your new parts
engine mounts
top end gaskets
carburetor rebuild/tuning (non-81)
ignition recurve (non-81... not sure you can recurve and run the '81 computer that controls the carb/dizzy).

You will have a very stealthy combination that comes close to that 150hp increase. If it were me, I would add emissions headers (Hedmann #68301) and freer flowing exhaust with super turbo mufflers to seal the deal.

 

Most States are giving up on Emissions when the car gets to 20-25 years old you might want to check. Since the 81's are so covered up in Stuff one can barley see the heads anyway and painted the corect color never tell. I'd bolt on a set of AFR's, and give comp cams a call and tell them what You have for a Cam. Short of that a set of late C4 Heads, Vortec Truck Heads, or any other aftermarket heads. You may notice that I'm not mentioning any OEM Iron Heads, as there time has come and gone.