Double Hump thoughts:

[Rusty Nail]

New board is wack.

 

[Rusty Nail]

I bought a #186 head one time - just the one head.... Dude asked me what I was gonna do with it ?

"Keep lookin for another."

I never did though.

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Told that story before, it's still sittin here if ya need ONE , I got you.
Maybe you can find one cheap on Craigslist too! Think I got $20 in it.

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[Bextreme04]

You bring up a good point. I've been tempted to go with vortecs, but have always shied away due to the cracking issue. If the summit brand vortecs have been re-engineered with a bit more meat, as you say, is the cracking still an issue that I'd need to be worried about?

Chevrolet performance and Jegs sell the actual new Vortec heads using a chevy casting, but the new castings are better and don't have the cracking problems that are common on the original castings. Summit "Vortec" heads are actually a Dart or World Products casting that is slightly different from the chevrolet performance castings. They have a slightly bigger chamber size at 67cc than the original Vortec heads that are 64cc.

 

[cstew47]

Found a set of rebuilt double hump heads (casting # 3782461) that I can pick up for 400 bones. I've been toying the idea of getting a better flowing set of heads to go with a RV torque cam for my 83 K20, and thought this might fit the bill.

What say y'all?

To me it depends on the condition. There are some good new budget aluminum heads on the market like Brodix or Promaxx that can be acquired for $800 - 1100 fully built. If you have to machine and buy components for the camel humps, it may not be the best move.

 

[cstew47]

After I posted this, I was thinking the same thing. Just too much trouble.

I've had my eye on the 152123s for a while now. I'm thinking that with those heads, and an 1103 cam, it should wake this 68,000 mile motor up at bit.

How does that sound?

I don't know what all of those numbers mean, but, remember, it is a system. You need to match the pistons, cam, and heads with your rpm range. Being a truck, I would assume you want a power band in the 1000-4500 range. If you are going to change heads, it is important to know the specs of your pistons or you might find yourself with a detonation problem.

 

[potent rodent]

I agree, don't bother with the double hump heads. There's no way whoever you bought them from could document what they've been through. It would be a shame to do all the work they would need just to have them crack the first time you got into it. There are great heads after market that would hold up forever and do more than you could ever get out of those old heads. Keep them though, you never know what they'll be worth in a couple of decades.
I do have Z28 heads on my engine only because it's a whole Z28 engine with better 300 hp heads we found that had been milled .020". So we machined them out to 2.02" x 1.60", stainless valves, polished the combustion chamber, and gasket matched it. Then I got a set of Lunadi roller rockers, Melling performance springs. Oh yeah, we put in the hardened exhaust seats and did the three angle valve job on the seat and the valves. No fancy retainers or high locks, just what came with the springs. Was it worth it over just getting a pair of Edlebrock heads or Vortecs? I don't know. I just wanted a real Z28 engine in my truck, it already had a real Z28 short block in it from the factory and we all stood there looking at each other wondering how the heck a Z28 engine got in a light duty pickup, and that's what I got.

do u have the org dz engine or the lt1 350 ?

 

[potent rodent]

i would like to see some numbers off the block and numbers on the pad below the pass side head

 

[Raider L]

That's right. I forgot about the accessory bolt holes, or the lack there of. There aren't any. And with your engine you'd need all you could get.