882 Heads from 74 Corvette

There are a set of 883 heads from a 74 Vette for sale locally. They have new seals and guides. Are they worth picking up for cheap? I am not sure what heads my 76 350 has (stock), but I am guessing the 882s probably aren't any better than what I have.

76 Malibu wrote:There are a set of 883 heads from a 74 Vette for sale locally. They have new seals and guides. Are they worth picking up for cheap? I am not sure what heads my 76 350 has (stock), but I am guessing the 883s probably aren't any better than what I have.

883 ? or are they 882 ??

Limey SE wrote:

883 ? or are they 882 ??

Sorry, 882 heads

Pull a valve cover off yours quick and see. I was never impressed by them.

Are you looking to keep your engine numbers matching / year correct?

The car is still in storage, so can't pull the valve covers just yet. I am not interested in keeping the car bone stock. Eventually I plan to build this 350 to make some decent power. The plan this year was a intake and carb swap.

In that case, I encourage you to acquire a pair of Chevrolet Bow Tie phase 2 cylinder heads (part number 14011034). They are the best cast iron heads Chevy ever made for the small block. They have angled plugs, 2.02 intake, 1.60 exhaust, and true 64cc combustion chamber volume. I've been running those heads on my car since the 1990s.

As for air/fuel delivery, on my latest build, I upgraded to an Edelbrock Performer RPM Q-Jet intake manifold topped off with a Q-Jet I built and tweaked myself. The combination works great for my needs; daily driver with LOTS of umpf.

882's are slightly better than 624's, but that is like saying that one broken leg is better than a broken leg and broken arm. I do get a little sarcastic! 882 are light weight castings and prone to cracking, 624's are even lighter and more prone to cracking. If you want to go with stock open chamber smog heads, 441's, 487's and 993's are heavy weight castings and much less prone to cracking. But if you are going to spend money on heads, there are much better flowing heads than the stock ones - back in the 1980's we would sell our first born for a set of Bow Tie heads, the phase 2 ones flow well and are as tough as they come. There are also many aftermarket offerings that make any stock head look like a boat anchor, 30 years ago that was not the case.

A good reasonably priced aftermarket head is the EngineQuest Vortec, a heavier casting than the factory Vortec not to even mention the Mexican Vortec heads.

I think the vortec head is the most affordable good flowing option. After that I would look at entry level aluminum heads. Machine work and parts are not cheap right now so to rebuild any cast iron head will cost as much or more than an aluminum head and still not flow as well or Have the weight and detonation gains from an aluminum head.

Iggy wrote:A good reasonably priced aftermarket head is the EngineQuest Vortec…

I just took a look at their EQ-CC200BA heads; it looks to be their version of Phase 2 Chevy Bow Tie heads. Could be a budget conscious direct bolt-on without having to spend extra on an intake with a Vortec bolt pattern.

Thanks guys, I will probably pass on the 882s. I have to do valve seals on my heads, so I figured these ones were maybe a better alternative with fresh seals and guides. They were never intended to be a long term solution. But getting the manifolds off to the swap to thet news heads probably means broken bolts. And then I'd be thinking of headers and that means exhaust work...mission creep sets in. So I will keep simple and do the carb and intake swap, along with new valve seals.

Thanks for the information heads. When money allows I want to do a full rebuild and the stock heads will not be reused. The bowtie heads sound great, but I don't know how easy they are to find. So I may have to go aftermarket. I also like the old school look of perimeter bolt heads too and it means I can keep my new Eddy intake and Q-Jet.

When you do finally get around to getting new heads, one thing to consider (other than performance, of course) is the valve cover bolt pattern like you mentioned and the end bolt pattern for accessories like alternator, power steering, AC compressor.

I had to be very budget conscious with my first performance build back in the mid 1980s. I managed to find a pair of double hump “fuelie” heads fully assembled with 2.02 intake / 1.60 exhaust valves, ported, polished, performance valve springs with aluminum spring retainers, valve guides machined for teflon valve stem seals, all for (I think) about $150.00 (maybe $200). I couldn't pass on that deal. The odd thing was they weren't machined for screw-in rocker studs; they still had the pressed in studs with retaining pins — go figure. The only issue was they didn't have the bolt holes on the ends for the AC compressor or the alternator. Being young and impetuous, I sacrificed the AC but had to drill and tap a hole to mount the alternator. A few years after moving to a warmer climate, I had to rebuild the engine and by that time (1992?), I bought a pair of new Bow Tie heads from PAW which have all the right bolt holes in them. I very much like AC in my PLC so I was eager to put it all back together. Speaking for myself, I've been very happy with these heads since I got them more than 300K miles ago.

As for headers, I have a pair of headman headers that went right in and have no clearance issues with sparkplugs. But, that will be down the road for you.

Put a cast crank in with a 3.750 stroke.  With  a 0.30 overbore, it will give you 383 CID.  388 CID with a 0.60 overbore.  I don't recall the name of the company I use, but they have been casting these new GM 400 SBC cranks, and they do not need to be externally balanced.  The rod journals are hollow to assist with this, and they sale 6" H beem rods to pair with them.  Use 1mm, 1mm, 3mm Total Seal rings or 1/16, etc.  to reduce friction.  The 6" rods will cause it to dwell at TDC,  so you will have more time for a complete burn of gases, and the longer stroke will allow your piston to spend more time drawing fresh air into the chamber while the valve is open, and then give you more dynamic compression.  It is important that you match this with a good flowing head, AFR is always a safe bet, then match your cam events and LSA to the Heads. 1.65 Roller Rockers on the Intake, and 1.6 on the exhaust will get your valve open sooner and get more flow started early.  Hollow valve stems, Conical Valve springs will allow you to rev up to or past 7,000 rpm 550 Horsepower and 500 lb ft is easily doable, but get a forged piston over 500 HP.  Get a 1987 4 bolt block, but nothing any newer or it wont hold up.  You don't need a roller cam if you have trouble sourcing the newer block, or are not interested in the additional expense.  2 1/2 " duals will be able to support 550 - 570 HP, but get good Low restriction mufflers, and upgrade your fuel pump. You can get an Edelbrock Victor manifold ported from Wilson manifolds for $1k which will be ported and gasket matched to your heads, NO POLISHING.  Turbulence is needed to keep the atomized fuel from falling out of suspensionThe trick oil pan will also be $1k, but you can use the Canton part which detects low oi pressure and injects some into the system.  If you purchase 18 degree heads, you will need to buy an intake manifold to match it, so buy the 13 degree heads.  Match this with an overdrive trans like the 22R4, 6 speed or the ZF 8 HP and you will have power at the range your in, always.  You will need posi, and 315mm tires in the rear.  Sticky 200 radials and some attention to the 4 link and you may be lightening your front end quite a bit.  It will be our last Internal Combustion build!
You can swap heads now. If the exhaust manifold bolts break off, they will be in the old heads, BUT, when I rebuild heads I usually blow out the bottom end. I prefer to do it at once if I can. And use studs when you get the al heads.

I'm running stock '74 "heavy" 882s on the 9:1 355 in my Sprint. They are among the better 76cc chamber smog heads; other castings in this realm are the 487, 487x, and US 993s. 441/441x castings are also a consideration, but watch out for the 80cc variants. 882s were used on many 350 and 400 passenger cars to include the L82 Corvette and Camaro Z/28 of the day. The later "lightweight" 882s should be avoided. I have a spare set of '72 993s as well, the castings have less flash and I've heard the intake ports are better. Decent GM heads that work with all your stock stuff and can be ported for better street performance.
The Bowtie Phase I/II heads, like the over-the-counter 292 and 492 prior, are ANGLE PLUG. These heads are the best performance iron units that GM offered prior to the Vortec design. HOWEVER, the angle plugs will cause issues with header clearance and offer no tangible benefit on the street over mildly worked assembly line straight plug heads. Most Bowtie heads will also be small chamber units that will likely bump your compression past pump gas levels.
The Vortec L31 truck heads are an inexpensive way to make a 350hp 350, but there are drawbacks. Special intake. Loss of provisions for factory wire looming with the center bolt covers. If you got the GMPP Fast Burn heads, I believe they have a dual pattern valve cover arrangement so that you can run the earlier perimeter bolt covers.
Aluminum Heads: don't buy the overseas garbage that you find on Amazon and eBay. The quality control is often poor. Any new aftermarket heads you buy should go to a machine shop for inspection, period.
Just my two cents.

Forgot to mention the "double hump" heads. Early 291, 461, and 462 castings are not accessory bolt hole units and you don't want them for your application. Like Zucchi said.
The later 186, 370, and 492 (straight plug version) are somewhat pricey, but still quite obtainable. These were the factory HP heads on the late 60s early 70s muscle SBC and have accessory bolt holes. There is also an 041 casting that is very similar to the 186, but does not have external double hump identifier and therefore is less costly (I also have a set of these for my future 406 build).
One important thing to note about all of these is that they are somewhere in the 64cc chamber neighborhood, which with a flat top piston in a 350 will put you at 10:1. These things are pre-unleaded fuel and will also have to have hardened exhaust seats installed.

Thanks. I never did buy these, and it turns out my car already had 882 heads anyway.