I posted this as a reply on another post, but wasn't getting alot of replies, so I though creating my own might help.

Anyway, I just bought a pair of complete set of '69 427 '074' heads for $550 shipped from a ebay seller (haven't received them yet). They need springs and a valve job, maybe guides before going on my 454. Like alot of heads from this vintage, they have had some repair work done on one of the rocker arm stud bosses on each head. I'm no pro, but the work looks okay and will be checked by my machinist before doing any more work.


Did I make a good deal or did I just take it in the pants?

Here are some pics:

http://www.chevelles.com/showroom/bluerebl/71_1_b.jpg

http://www.chevelles.com/showroom/bluerebl/72_1.jpg

http://www.chevelles.com/showroom/bluerebl/cc_1.jpg

http://www.chevelles.com/showroom/bluerebl/da_1.jpg

http://www.chevelles.com/showroom/bluerebl/e0_1.jpg

From what I read '074' heads are suppost to be round exhaust port heads. From the pics they appear to have "D" shaped exhaust ports. Its been suggested that they might of been modified for the "D" ports.


I want them for my 454 going into my Datsun 280z, the weight reduction over iron heads should help alittle. I was planning on using a pair of '241' open chamber heads with the big valve treatment. Will these heads perform the same, better?

I think I'll be running a Victor Jr. or a Team G single plane intake. Click the link in my sig to get the post on the little Z.

Thanks guys!!

A tripower! Actually a GM #163 or rpm is fine. I'd use the Mr. Gasket #5828 Ultraseal gasket, mathces the ports really closely.

They're simply OK heads, with a real need to raise the exhasut floor. You have the better D shaped ports, mine are round ex ports.( they came with both and people did weld the floors on the O ports) Be sure to use rocker studs with extra-long threads on the exhaust bosses, and we double helicoiled them all. Overkill maybe, but I'll never break one again.

You got a great deal for $550. Theses old heads will take a lot of dcr and do need to be run hot ( like using a 195 thromostat) to make best power.

But they're old, fragile castings ( I will never lift a motor with them). I had some anti-freeze seep into #7 runner due to some porosity. Simply JB welded the backside(water jacket).

Fitted with 2.19/1.88 Ferrea valves and a raduis valve job, they seem to make really decent power though! Polish up real nice too!

They appear to have been D-ported although the port could have been made a little smaller. That is the only real problem with them aside from the poor alum. quality of the early castings. I would recommend staying away from a roller cam that requires a lot of spring pressure. As you can see the rocker stud bosses really don't like it. They should work just fine for your application.

Originally posted by 427L88:
I had some anti-freeze seep into #7 runner due to some porosity. Simply JB welded the backside(water jacket).

Someone suggested to me about epoxy coating the heads to "seal" up the bad porosity.

Any thoughts on this, or what to use (brand, etc)?


Originally posted by Mike Feudo:
They appear to have been D-ported although the port could have been made a little smaller. That is the only real problem with them aside from the poor alum. quality of the early castings. I would recommend staying away from a roller cam that requires a lot of spring pressure. As you can see the rocker stud bosses really don't like it. They should work just fine for your application. Thanks Mike, the cam is the same one that I've used in the past and alot of members are running, UltraDyne-Lunati Solid Flat Tappet Cam 288/296F10: .612/.630" lift, 288/296 adv, 255/263 dur@0.50", 110 LSA.

So the open spring pressure won't be extreme like a roller spring.

Hopefully I won't have any problems with the rocker arm stud bosses.

I wonder if a stud girdle would add extra insurance?

Yes, I would recommend a stud girdle.
Anything that helps support the studs is a good idea as like Mike said the stud bosses are pretty fragile.
And definitely the long bottom studs

Originally posted by Wolfplace:
Yes, I would recommend a stud girdle.
Anything that helps support the studs is a good idea as like Mike said the stud bosses are pretty fragile.
And definitely the long bottom studs I guess you learn something new everyday, I thought stock studs bottomed into the head. Anyone got an ARP part number for the studs?

Update:

I received the heads today. There are a couple of things that the seller failed to mention (always happens).

#1. ALL the intake mounting holes have been heli-coiled. Its not a bad thing really, but I would like to of known.

#2. I can clearly see a very thin crack down an intake runner. Its under the area where a rocker stud bosses was previously broken and repaired (tig welded). The end of the crack has a very small tig weld near the openning into the runner. I imagine that the crack is prob sealed (its being pressure checked to be sure), but again I would of liked it mentioned in the auction.


Regardless, I still feel that it was a good deal. Hopefully, the machine shop won't have any bad news for me. They are being dropped off tommorrow, I guess I'll know soon.

Lastly, will these heads support 500HP on my 454, as is "stock"?

Here's my combo:

Bottom End:

-454 Block Bored 0.030", Honed w/Torque plate
-4.00" 454 Forged Steel Crank Turned .10/.10
-Stock BBC 3/8" I-Beam Rods w/ARP Bolts
-9.0:1 CR L2399F TRW Forged Pistons w/matched moly rings
-Clevite 77 Main/Rod/Cam Bearings


Up Top:

-Aluminum GM '074 Rect Port BBC Heads, 2.19/1.88" SS valves
-Crane "Bulk" .650" lift springs
-UltraDyne-Lunati Solid Flat Tappet 288/296 F10: .612/.630" lift, 288/296 adv, 255/263 dur@0.50", 110 LSA
-Oil Pin Solid Lifters
-3/8's One-Piece Chromemoly Welded Pushrods
-1.72:1 Comp Magnum Roller Rockers
-Victor Jr. Single Plane Intake
-850 cfm Holley Double Pumper
-GM HEI Dist w/Crane LX-2 Fireball Coil
-Crane HI-6 Ignition


Thanks again guys!!!

Originally posted by bluerebl:
Update:


Lastly, will these heads support 500HP on my 454, as is "stock"?

Here's my combo:

Bottom End:

-454 Block Bored 0.030", Honed w/Torque plate
-4.00" 454 Forged Steel Crank Turned .10/.10
-Stock BBC 3/8" I-Beam Rods w/ARP Bolts
-9.0:1 CR L2399F TRW Forged Pistons w/matched moly rings
-Clevite 77 Main/Rod/Cam Bearings


Up Top:

-Aluminum GM '074 Rect Port BBC Heads, 2.19/1.88" SS valves
-Crane "Bulk" .650" lift springs
-UltraDyne-Lunati Solid Flat Tappet 288/296 F10: .612/.630" lift, 288/296 adv, 255/263 dur@0.50", 110 LSA
-Oil Pin Solid Lifters
-3/8's One-Piece Chromemoly Welded Pushrods
-1.72:1 Comp Magnum Roller Rockers
-Victor Jr. Single Plane Intake
-850 cfm Holley Double Pumper
-GM HEI Dist w/Crane LX-2 Fireball Coil
-Crane HI-6 Ignition


Thanks again guys!!! =
I like you definition of "stock" :D
Yes they will support 500+HP graemlins/thumbsup.gif
Use a stud girdle, it will help support the already weak stud bosses.
Check the chambers to see where your compression actually is,,, it would be nice to get it to 10.0 or so.

Originally posted by Wolfplace:
I like you definition of "stock" :D
Yes they will support 500+HP graemlins/thumbsup.gif
Use a stud girdle, it will help support the already weak stud bosses.
Check the chambers to see where your compression actually is,,, it would be nice to get it to 10.0 or so. Well, I meant to say the heads being "stock" ZL1 config.

In any case, I should get 9.25:1 CR with my heads and ZERO decking the block w/ a 0.039" head gasket.

I am highly considering a 150HP nitrous hit. Do you see any problems doing that with these heads Mike?

Nope,, 150 is pretty safe as long as you have a decent fuel system ;)

A friend had a stock street weight 66 Vette with a set of those on a 482. Driving it out and granny shifting it went 10.11 at 144+. The horse power can be made but the newer heads make it much easier and are definitely a better quality alum.

Originally posted by Wolfplace:
Nope,, 150 is pretty safe as long as you have a decent fuel system ;) I had planned on running C-16 fuel to the nitrous line via a seperate 2 gallon fuel cell with its own fuel pump.

Of course the carb will be fed with a Carter 172, maybe a "helper" electric fuel pump when racing.

You're building almost exactly the same motor I am, Cable. The ONLY difference is that I'm going to run the GMPP Sig Series heads (picked them up for a great price). Should be interesting to see how things come out. Keep us posted!! graemlins/thumbsup.gif

Originally posted by SS_Sean:
You're building almost exactly the same motor I am, Cable. The ONLY difference is that I'm going to run the GMPP Sig Series heads (picked them up for a great price). Should be interesting to see how things come out. Keep us posted!! graemlins/thumbsup.gif Are you running the same L2399 pistons? I ask because I am worried about valve to piston clearance issues.

Well, I got the damage report on the heads....


My machinist will be using my Eaton 2.19/1.88" SS valves, my Crane bulk .650" springs, and my chrome-moly L-88 retainers and locks.

Everything else he's supplying or laboring.

He is going to re-weld the existing damage, fix the intake runner crack, and weld-fill countless dings on the head gasket sealing surfaces.

The existing bronze guides are in good shape, but I am considering having him replace them anyway.

So, after the weld work, valve job, and assembly the grand total comes to $600. Not bad considering the work being done.