YeagerSP

Hi all, I'm not too informed on what I should do to my 350 engine. The original heads cracked on my 84 vette, so I did some research and I'm thinking about going with 041 heads. My question is will the 041 heads need anything done to them before I can put them on my stock motor, if so what is a good performance/daily driver head instead that I could just bolt on?

Hot Rod Roy

The 041 head is a good one, if you don't need to meet some tight smog requirements. It has a smaller combustion chamber than your original 624's, so will raise your compression ratio. Here's some info for you:


You may need to run mid grade, or maybe premium gas with the 041 heads. I'd suggest at least lapping the valves before you install the heads. Place the heads face down, then squirt some "spray lube" (WD-40 or the like) on the back of the valves. Look for leakage into the combustion chambers.

I don't know if the 041 heads have valve stem seals. You might want to upgrade to the later '84 style seals, and maybe even use the '84 exhaust valve rotators from your 624 heads.

I put a set of 993 heads on my '84, because I have to meet California smog laws. My car runs good and passes smog with flying colors!

BLUE1972

jackson

? can you fit '85-'90 L98 aluminum heads C/N 10088113 ?

10088113 aka ZZ4 head P/N 12556463 ... relatively small 58cc chambers & 0.1" raised D-port exhausts ... no longer in production

Hot Rod Roy

The '84 heads (624) have an internal exhaust passage that is used for the EGR. The aluminum heads don't have that internal passage. That's why L98's have that d***n tinfoil pipe across the RH rocker cover! The 041 heads also have that internal passage.

GregMartin

I guess it depends on whether or not you need to pass emissions testing and what’s involved in the test. I don’t have to, so I put a set of edelbrock e street heads on my 84. They have 64cm combustion chambers so the compression is up a bit. I am very happy with them but they do not have the EGR transfer ports so no good if you need to keep the EGR.
Not sure about the zz4 heads but I thought they were Vortec heads and if so the intake ports etc are different

Edit
I just looked up ZZ4 crate engines and I’m wrong about the vortec heads it looks like they have aluminum corvette heads.

YeagerSP

My state doesn't have any smog laws. So I could pretty much just buy 041 heads and have a mechanic bolt them on? I don't have much expendable for extras.

Hot Rod Roy

That's a bet I wouldn't take. How do you know the heads are good? If you loose the gamble, you'll get to pay again!

YeagerSP

Assuming the heads aren't cracked though, could I have the mechanic bolt them on easily, without having to change my manifold or do some machining? Sorry, I don't know much about this.

cv67

Check them first
Mag
Ck valve job, guides, srpings and seals a given
Do the math.

Too many shortcut and pay/do it allll over again cause they cheaped out.

Hot Rod Roy

You do know the story about "Assume" don't you? Yes, the heads will bolt on without modifying anything. If your mechanic is good, he will recommend that they be checked out before you install them. As an absolute bare minimum, do the valve leak test I mentioned.

While you have the manifold off, you should really spend some time enlarging the manifold ports. You'll see why when you get that manifold off!

YeagerSP

Thanks for the insight. I do ave plans to take them to a shop for testing before I had them put on my car, but thanks for making sure I knew to do that.

GregMartin

Take Roy’s good advice and do this, you’ll thank him later.

84 4+3

For around 600, you could do a set of iron summit heads and they'll bolt up and be perfectly fine too. If you get the 041 heads and they don't need work you'll be ahead but once you start throwing machining and guides in... may be the better route. Food for thought.

Hot Rod Roy

This guy is a bit over the top, but he's showing the valve seepage problem I mentioned: Enjoy!

ghoastrider1

If you buy used heads, be sure to have them checked for cracks. I found one crack on the Vortic heads I bought. No recorse but to buy another uncracked one.

GregMartin

I guess you don’t want to over invest but you can get a set of Edelbrock 5089 E-Street heads from Summit for a thousand bucks https://www.summitracing.com/parts/e...SABEgKIN_D_BwE
Mine are great but if that’s out of the question what about a set of 113 aluminum Corvette heads?

84 4+3

The 113s would on an other wise stock l83, have a compression ratio of over 11:1... I'd be a little nervous about that. And aren't the center bolt holes at a weird angle?

GregMartin

What size combination chambers do 113s have.76cc, 64cc, 58cc? 64cc chambers are about 10:1 static or 9.4:1 dynamic depending on the cam. Also I would use felpro 1010 gaskets that compress to 0.039” so that gives a little bit of space.

84 4+3

56 I think. Been a while lol.