I may have found some heads for my 454 bracket racer project. They're GMPP Aluminum, part #12363410, never used. As I've said I'm looking to spin this thing up pretty good, with a duration in the 260-270 range (@ .050), and a .600+ lift, with a shift in the area of 6500-7500 RPM's (I haven't settled on where, exactly, yet). I would prefer to run more compression, and obviously aluminum would allow me to do that.

The heads that came with my motor are 781's, and have smaller valves than I had hoped for. I didn't have a micrometer, but using a ruler they looked to be in the neighborhood of 2.02/1.74. They were rebuilt, obviously, but will need the appropriate 2.19/1.88's. I had the heads on my chevelle done with this size, and they ended up costing a little over a $1200 to have them done. You get where I'm going with that, right?

The guy wants $900 for them. They've been sitting in his closet, never bolted up to a motor. Does this sound like a good deal, and do these look like they would work for me. I know some of you will say 781's flow well into the .600 lift range, and they aren't necessary, but I was also looking at the compression consideration, and the cost consideration. These heads will flow better than stock iron, dissipate heat faster, and allow more compression.

I have to say, I'm venturing into an area of performance I've never been in, and that's why I'm relying on opinions from you good folks. Thanks for your help!!

The motor:

http://webpages.charter.net/seanthomas/454-3-1.jpg


Here's the info from GMPP on them:

12363410 Signature Series Aluminum "Rectangle" Cylinder Head
This Cylinder head fits all 1965-1996 Mark IV and GEN V and VI 396 thu 502 cubic inch Big Block Chevrolet engines. They are fully machined with semi-finished bronze alloy guides and semi-finished valve seats that use 2.19/1.88" valves. These high velocity 315cc long intake runner and 300cc short runners enhance mid-range throttle response and torque. The exhaust runner volume is 110cc. The 118cc semi-open combustion chamber design will make a very streetable compression ratio. Spring DIA is 1.55", with 7/16" rocker stud holes. These accept all stock accessory brackets except GEN V where the bracket holes have been enlarged to 7/16". The rocker studs and exhaust bolt holes are heli-coiled for strength. Intake and exhaust ports are in stock locations.

Technical Notes: These heads are made from 356-T6 aluminum alloy. The 9/16" deck surface is for maximum strength and great head gasket sealing. Designed for 3/8" push rod diameter. These heads require cylinder head bolt kit P/N12367779. Use the following performance head gasket 1965-1990 with standard bore to 4.370" use P/N 12363414 and with 4.47" to 4.540" use P/N 12363413, and with Gen 1991-1996 engines with standard to 4.370" use P/N 12363412, with bores of 4.47" to 4.54" use gasket P/N 12363411. The semi-finished bronze guide can be finished either 11/32" or 3/ 8" . The interlocking hardened valve seat will accept leaded or unleaded gas. Use intake gasket P/N 12511789.

http://www.gmgoodwrench.com/gmgoodwrenchjsp/perfparts/partlist.jsp?cat=9338&section=ep

never mind, my post really added no value

Sean
Go to the Edelbrocks web site and look at the Performer RPM 454 heads. They are basically the same thing, Edelbrock makes the GMPP heads as far as I know. All of thier heads are top quality from what I have seen of them.

I'm not sure how that's going to help, Bill. I've got the Edel catalog, and the info supplied is pretty slim.

Sean,for $900 I'd grab them graemlins/thumbsup.gif
(those are deals that find smile.gif run over there with $900 for those!)
BTW,the stock valves in your 781's are 2.06/1.72

Sean,
The web site has all of the flow data at different lifts, the spring pressures etc. Actually, I am fairly sure that the same info is in the catalog. Don't know what else you would need to decide if the heads will do the job for you.

Bill, my catalog is an '01 or '02...they must have put more info in...and I think you're right. Edel makes GMPP heads, and marks them up higher. Thanks, though.

A pair or each??

A pair, grab them quick!!

Each, please consider Canfields...

pdq67

A pair. It'll be about $300 for Manley valves, and springs will have to be done as the motor is assembled. So I'm looking at around $1,400 for the heads, complete. The loaded Edel's list for almost $1,800.

The question is...will these rectal's work for my performance goals? The last thing I need is a set of heads I can't use sitting around. I'd have to make a coffee table out of them, or something. ;) :D

Anyone? :confused:

i probably would get them if it were me, but if you're having doubts about them, then don't. though you could probably sell them later on if you decide you don't like them.

I'm not having doubts about them. I just wanted to get the appropriate heads for what I'm doing.

Get them. They'll be fine and provide you much more punch in the 5500-7000 range than any oval head will, assuming you are building something to run in that power range, i.e. 4.30+ rear gear.

And then there's the nitrous, OY VEY!

whoops, sorry.

The heads will be fine. Nine hundred dollars is a good buy for a pair of these heads. If you don't mess with the combustion chambers or put oversize valves in them you can always sell them to an NHRA Super Stock racer and probably make money. These are the same heads Armstrong went 8.97 in SS/BA with.

Thanks for the thoughts, guys. The heads are on their way!