[Chris65LeMans]

Well, I sent my heads out to a machine shop for some work after losing compression in cylinders 2 and 4. Just got the call that the heads are cracked and are junk. Time for some new heads.

I've rebuilt pretty much everything on my car except the engine. It is a 400 out of a '69 Firebird and has

A. 96 heads that had substantial work done to them and roller rockers.
B. Cam was described to me as an Engle EP-25. Lift .507" (both Ex and In), 280 degrees duration, .338" lift (both In and Ex)
C.The motor is described as being stroked to 440 CU.
Ca. Holley 4160 Carb that has been set up like a 4150. (Ford bowls, secondary (non adjustable) metering block added.
Cb. Edelbrock P4B intake
D. New 11 bolt water pump
E. new mechanical fuel pump
F. DUI distributor
G. M21 4-speed
H. 3.71 12-bolt rear
I. I estimate crank horsepower at 450.

I haven't confirmed B or C or the "substantial work" noted in A above, but don't have any reason to doubt it based on the way the engine performed and behaved.

I no longer have time to do my own wrenching (Kid's sports getting busy, and I've got 3 of them), so I have it at a good mechanic's shop.

Any suggestions for heads? The mechanic said he couldn't find any iron heads, so he suggested some Edelbrocks. I said I don't want to bolt them on out of the box, so he's going to call some local perfomance shops for some ideas.

Thanks in advance, Chris

[Chris65LeMans]

Here are some photos. Exhaust is 3-tube Headman headers, 3 inch exhaust with no X pipe, Magnaflow mufflers, and 2 1/2 inch over the rear end.



https://forums.maxperformanceinc.com...1&d=1617127870

[geeteeohguy]

My 2 cents: about 15 years ago I had a set of iron #15's done for my '67 400. I wanted 9:1 CR, and these had the 87cc chamber. My heads needed new seats, screw in stud upgrade, new valves, new springs, you name it. I spent $1400. Had I known prior to getting sucked into the vortex, I would have been ahead of the game buying KRE's or ED's for $600 more at the time. I personally would be inclined to use KRE over Edelbrocks, but that's just me. All my Pontiacs have always had iron heads.

[steve25]

The first question that you need to answer is if you want to stick with iron heads, or go with aftermarket Aluminum D port heads.

The aftermarket heads will flow like your ported 96 castings did or better, in terms of iron heads maybe you can turn up a used set ported and near ready to bolt on, if not and you want to have the Same level of power you had before( assuming the heads where ported right to make good power! ) then the iron castings you get will need to be ported.


Also unless your cracked 1971 96 castings where milled a ton your motor as it was would not have had but maybe 8..8 compression, and now that you have the chance you should get that up to at least 9.4 with a iron head, or 10.5 with a Aluminum head.

One thing that greatly concerns me is that if I read you correctly, both of your iron heads cracked. No?

This would make me worry that the motor got hot enough to cause the rings to loose some of there needed tension to seal up well when the motor is running!

Also I would carefully check the block deck surfaces in between the cylinders with a feeler gauge straight edge to confirm that they are no more then .002” out of wack.

I would also confirm that the motor is stroked since that will change your compression greatly. And it should be very easy with the heads off to check if you still have a 400 with a 3.750” stroke, or a 440 with a 4.00” stroke.

[PAUL K]

If the 96 heads are worth saving they can be fixed for a lot less money than a set of aluminum heads. We would be a few months before we could get to them but if you want to get an idea on cost call Indy cylinder head. There is also a shop in Iowa that uses the same method as Indy but is probably going to be considerably cheaper.

[JLMounce]

I'd be verifying actual bore/stroke as well as the cam. The cam maybe to a lesser degree, but you really want that bore and stroke information to make a more informed choice on the heads.

You don't want to assume it's a 440 and go too large on the chamber if it's actually not. Or conversely, go small on the chamber under an assumption it's something like a 406.

If you are wanting to do any upgrades, now is a good time to do them. A good chunk of the engine is torn apart at this point. At minimum I'd be taking the valley cover off, inspecting each cam lobe and lifter, inspect the distributor gear, check for part numbers on the crank, pistons, possibly rods if there's anything in view.

Basically learn as much about the combination as you can to help you make an informed decision.

If you're sticking with your current exhaust system, you know you need to go with D-ports. That leaves you with a factory head, Edelbrock D port and the KRE D port. I've had the KRE D's myself since early 2016 and haven't had an issue with them. Only thing I would have done different is I would have spent a bit extra up front to have a CNC program done on them instead of going as-cast.

[b-man]

Check the stroke with a measuring tape or ruler now that the heads are off.

Would be easy to the difference between 4.00” stroker crank and a stock 3.75” one.

[Steve C.]

X2 regarding Indy Cylinder head for repair on iron heads.


http://www.indyheads.com/about.html


.

[tom s]

I think the last time I used Indy for repair it was like $1500!Tom

[Sirrotica]

FWIW, this outfit does a lot of cast iron and aluminum repairs cylinder heads transmission, differential cases etc:

http://midwestcylinderhead.com/services.php#casting

I've heard they are top notch, and much less then Indy Cylinder Heads, they do it on a production basis, so I imagine their turn around is also quicker.

[Chris65LeMans]

Good info, everyone. Thank You!

Once I add up the cost of having the heads shipped somewhere, the repair costs, and the costs of towing my headless car home and back to the shop, I think I'm leaning towards going to aluminum.

I saw a few people on here say they preferred Kaufman heads to Edelbrocks. Why?

[b-man]

You’d be looking at $300 just to ship those iron heads back and forth. They’re not valuable round port heads, scrap them and buy aluminum.

Easy decision.

[PAUL K]

Originally Posted by tom s

I think the last time I used Indy for repair it was like $1500!Tom

They've been bought out not long ago. Haven't seen the cracked heads but at a reasonable shop $600 should fix the cracks.

[PAUL K]

Originally Posted by Sirrotica

FWIW, this outfit does a lot of cast iron and aluminum repairs cylinder heads transmission, differential cases etc:

http://midwestcylinderhead.com/services.php#casting

I've heard they are top notch, and much less then Indy Cylinder Heads, they do it on a production basis, so I imagine their turn around is also quicker.

If they're in Iowa that is a good place to deal with. I gave up after three clicks on their Website and not finding and address.

[JLMounce]

Originally Posted by Chris65LeMans

Good info, everyone. Thank You!

Once I add up the cost of having the heads shipped somewhere, the repair costs, and the costs of towing my headless car home and back to the shop, I think I'm leaning towards going to aluminum.

I saw a few people on here say they preferred Kaufman heads to Edelbrocks. Why?

There are two incredibly shallow, but meaningful to me reasons I went with the KRE D's over the Edelbrock D's.

1. The KRE's at least at the time were about $200.00 cheaper in total.
2. While not completely universally liked, KRE is a Pontiac community business that caters to Pontiac. Edelbrock had to be prodded for a while to even offer up a head to the Pontiac community.

In truth I don't think you can really go wrong with either head. especially if you're buying bare and having them built by your machinest.

[Chris65LeMans]

Got some updates from the mechanic:

1. They verified my 440 cu displacement by measuring.
2. I have asked them to verify cam specs
3. The cam has solid lifters
4. The 96 heads had 72 cc combustion chambers (95 stock?) with 215 cc intake runners.

The machine shop is telling the mechanic that they will "port & polish" the Edelbrock heads to make "them flow 18% better." The heads will not come with rockers or pushrods, so we'll need to choose some roller rockers and pushrods for them.

My questions are:

1. Is it possible that my 96 heads had such relatively small combustion chambers? Were they machined down that much, or did somebody measure wrong?
2. What size rockers will work best?
3. I want to have the same power level that I had before (about 450 hp at the crank) once I'm back up and running. Do I need to do any work to the heads? (I get the impression that the machine shop isn't planning any major work - yet.)

Thanks!

[tom s]

Chris,left you a phone message.Tom

[GTOLou]

Sounds like a good time to consider some of those speedmaster heads....

[DiamondJim]

My first concern is why did both heads crack. Do you have severe overheating problem? If so I would be concerned about the block as well. My thoughts are KRE D ports ported, cam and intake swap. For a similar solid flat tappet cam that will make more power I like this Lunati https://www.lunatipower.com/street-s...8-276-284.html If you set the heads up right you can run it with 1.65 rockers and it will work well.

[DiamondJim]

I would run the crower cool face solid lifters instead of the lunati