I currently have #17 heads off of a '74 400 on my 68 400. I'm rebuilding the motor, on a budget, and want to go from the current Dyno 220HP to around 350HP. I was told my current compression ratio is 8:1 and swapping out the #17 heads and installing the #64 heads would put me at 9.5:1 compression ratio and give me around 350HP with the right cam. The #64 heads are off of a 70 GTO 455 and are virgin.
Can somebody recommend a good cam for this setup? This car will be my daily driver when complete. I have swapped the Muncie for a more highway friendly Stage II 200R4. I'm running 3:36 gears in the 10 bolt posi rear-end.
I would look at the Summit 2801 kit. They are way cheap and I think somebody said Comp Cams grinds them for Summit. If you break it in right it should last a good long while.
I don't know where you got your 9.5 to 1 number from with the 64's unless there has been some moderate milling on the decks. 64 heads are 87 cc which equates to 8.6 to 1 on a 400.
64 heads are a great choice for a 428 or 455...but not for a 400.
Si Vis Pacem Parabellum
1967 Starlight black PMD Engineering 400 Auto 1968 Alpine Blue 400 4 speed 1968 Verdoro Green 400 HO 4 speed 2013 1LE 2SS/RS Inferno Orange Camaro.
Thanks for your response. Yes, there will most likely be some milling. We're planning on tearing the heads down in a few weeks and having them magna-fluxed and milled as needed. I need to understand compression ratio better. Could you please share your calculations for the equation you provided below. I researched and found several threads on Google stating the #64 heads on a 400 was a great idea, just doesn't happen often as they are hard to find. I know the #64 heads were built better with larger valves and screwed in studs. They will also allow the Dougs Headers I'm planning on installing to bolt right on. The guy helping me rebuild the heads is a Pontiac (exclusive builder) and stated this was the way to go.
Here's two of the articles. They will bolt right on and I should be over 300HP using pump gas...
Honestly..you'd be better off buying a new set of Edelbrock aluminum heads and selling the 64's.
By the time you spend the money on milling them on both intake and block side...you are in roughly $400 right there...not including the cost of SERDI cut if needed..guides, springs, valves, there is another potential $500 to $1000.
I have issue with taking a perfectly fine one year only casting and ripping it down 40 thousandths on 2 sides and unnecessarily writing off $400 just to get down to 80 cc chambers.
If it were me...id sell the 64's as is..you could get 900 to 1300 for them...then find a set of new Edelbrocks. Think about it...by the time you spend the money on iron heads...you could have a new set of heads that will suit your needs right out of the box...have better performance...and coupled with the RPM cam and intake...be pretty stout.
Si Vis Pacem Parabellum
1967 Starlight black PMD Engineering 400 Auto 1968 Alpine Blue 400 4 speed 1968 Verdoro Green 400 HO 4 speed 2013 1LE 2SS/RS Inferno Orange Camaro.
You would have to take heads down to 77 cc for 9.5 to 1. Thats 10 cc's off the deck. Thats INSANE to spend usually $50 per 2 cc's removed from surface...that is $250 on the intake side and $250 on the block side...or $500 just to get the compression ratio where you want it.
So...$1000 for heads...plus $500 saved on milling plus $750 for head build (not inc milling) $2250..
I would seriously consider another option...especially one that would bolt up to Dougs headers..give you better performance...lighter...and a proven package with the Edelbrock RPM cam package.
Not to mention the HUGE weight savings over iron heads and intake.
Just my opinion...
Si Vis Pacem Parabellum
1967 Starlight black PMD Engineering 400 Auto 1968 Alpine Blue 400 4 speed 1968 Verdoro Green 400 HO 4 speed 2013 1LE 2SS/RS Inferno Orange Camaro.
1968 400 Coupe, verdoro green, black vinyl top 1968 400 Convertible, verdoro green, black top 1971 Trans Am, cameo white, auto 1970 Buick Skylark Custom Convertible 350-4(driver)
Agreed...but even if zero decked..that only takes maybe 15 to 20 thousandths out of equation..which is maybe 3 to 4 cc's...or 6 to 7 cc's remaining to mill to get the desired compression ratio. With that...you're still paying to have the block zero decked if not currently.. plus the additional expense of still having to mill 35 to 40 off the head and some off intake decks..which would still equate to $500 to get the heads to 9.5 to 1.
After reading what I posted...i realize I was being quite direct. Reason? I made that same mistake before and understood I spent $1200 more on the heads and could have achieved better performance by selling very rare and highly sought after #64 heads and went to 72 cc E heads only spending a little more for ARP bolts and gaskets.
Took me 6 years to find a buyer for modified heads I paid $1850 in 2000 for (cores, parts and labor) and took a $900 loss because they were limited in use to only 400 and not 428/455 builds..
I saw a marked increase in performance and handling with the 72 cc E heads...lower radiator temps..and could tell with a 3.55 rear...definite seat of pants feel in horsepower.
Si Vis Pacem Parabellum
1967 Starlight black PMD Engineering 400 Auto 1968 Alpine Blue 400 4 speed 1968 Verdoro Green 400 HO 4 speed 2013 1LE 2SS/RS Inferno Orange Camaro.
After reading what I posted...i realize I was being quite direct.
Has anyone ever accused you of being too subtle? LOL!
1968 400 Coupe, verdoro green, black vinyl top 1968 400 Convertible, verdoro green, black top 1971 Trans Am, cameo white, auto 1970 Buick Skylark Custom Convertible 350-4(driver)
I'm not sure why I would have to mill at all. According to the calculator provided above, I would be as you pointed out earlier at 9:1 compression ratio and not 9.5:1. The #64 heads will provide me everything I believe I need for around $1200 after the rebuild is complete. As I stated in my initial post, I want to be between 300-350HP after the build and be able to run on pump fuel. I believe the #64s will get me over the 300HP with the right cam without milling. I'm currently at 220HP with my 1974 heads.
I would love to buy the Eddy's but do not have $2400 to drop on heads. Please verify my information above and recommend a cam which would add horsepower to a daily driver.
Stock deck height is .020 Bore 4.12 Stroke 3.75 Chambers 87 cc Piston valve reliefs 6.7 cc
Accounting only for standard bore, compression in 8.68 to 1 with 64 heads
With the small valve 350 #17 heads you have, the same calculator shows 9.94 to 1.
Unless I misread, you mentioned you wanted 9.5 to 1...I merely stated that unnecessarily spending money milling the bejesus out of perfectly good heads...that for a few hundred more..the E heads would be a perfect solution. $1000 for 64 heads and $1200 for money not spent on properly machining and building 64s to achieve your desired 9.5 to .
I also don't understand how with 72 cc #17 heads you only have 8 to 1 compression and with higher volume 87 cc #64's and no other machining you mentioned...you are at 9.1 to 1.
With larger combustion chambers as the 64's have...you LOSE compression. Somehow your #17 350 heads are 8 to 1 on your block when according to math...the answer is 9.9 to 1. And the same math you came up with..the 64's (absent any info provided) they are magically 9.1 to 1...when math shows they are 8.6 to 1.
Some sourced place your #17 heads at 72 cc...some say 80 cc. With 72 cc, they are 9.94 to 1 compression. With 80 cc...9.22 to 1. Now...taking into account the only differences in the parameters that affect anything is the chambers and valve size...you have larger valves with the 64s. In order to get the 9.5 to 1...you would need to mill a minimum of 7 cc's from the heads or block or a combination of both to achieve a 9.1 to 1 cr. Another 3 cc's would need to be milled to achieve 9.5 to 1.
My consensus is...if you bolt those heads onto the block with no other machine work, you will be at 8.6 to 1. Although your 17 heads have 9.2 compression now...yet smaller valves..putting the 64s on is a wash. Yes you have larger valves...but NOT the compression...so i surmise your new dyno run will fall flat on its face.
I guess i am stymied by how you got your numbers.
Si Vis Pacem Parabellum
1967 Starlight black PMD Engineering 400 Auto 1968 Alpine Blue 400 4 speed 1968 Verdoro Green 400 HO 4 speed 2013 1LE 2SS/RS Inferno Orange Camaro.
Agree with Banshee. Sell the 64's to someone restoring a 70 FB/GTO 455. E-hds will make more power and run cooler.
Example, Nothing exotic.
455 with box stock E-hds, RPM intake, RAIV cam, 1.75 headers, ETC. Can cruise around on 87 octane, and add 92-93 for the track. Average 11.90 to 12.00 @ 114 mph in 90 degree heat. Faster in good air. Only thing have do is put on a set of slicks and a helmet.
Oh ya. That's with letting the TH400 shift itself with 3.42 gears.
72 cc E heads out of box plus an RPM cam and 3.36...
Leave block deck at .020 compression 9.94 to 1. Mill block deck to 0...10.3 to 1
Can run safely with aluminum 1 point higher than iron heads with the accompanying performance gain.
All I am saying...is this.
By the time you modify what you have planned (heads and block)...you will have spent roughly $200 to $300 less than a ready to run set of 72 cc E heads. You will also reap the benefits of the headers you already have..plus the weight savings and have a cooler running engine, a very typical problem with Pontiac..and have maybe 30 to 40 more usable horsepower with the E heads.
I guess i'm having difficulty understanding the rationale of spending potentially $600 just to get a set of 455 heads to run at a desirable compression for a 400 not including the labor and material cost of building the heads.
Valve grind per used valve $8, SERDI valve job $200 to $250. New guides (never knurl) $100. Springs, new...to match cam $150 add locks and retainers.. $80... $550 just for basics not including labor to set up. So say $750. That's $1350 just in heads. Add the $1000 sale price of the 64's and you have your E heads.
I worked at a head/machine shop...those prices are rough as of 10 years ago. A machine shop would steer you to spend money in house over going the E head route I suggest...
I understand your goal...it's the cost/benefit ratio and your overall happiness with the end product that concerns me.
Si Vis Pacem Parabellum
1967 Starlight black PMD Engineering 400 Auto 1968 Alpine Blue 400 4 speed 1968 Verdoro Green 400 HO 4 speed 2013 1LE 2SS/RS Inferno Orange Camaro.
Ok, I admit you know much more than I do regarding heads and deck heights etc. I'm on here because I need help and am confused by guidance I'm getting locally. Let start over. First, I do not have $2400 to drop on new Edelbrock heads. Here's the problem statement...
I currently have a 400 out of a 1974 which I had Dyno'd at 220HP. The same 400 block in a 1968 Bird produced 320HP when I ask how the 68 was able to achieve more horsepower without Edelbrock aluminum heads I've been told they had different heads and cams. As we all know things changed by '74 and the government had restrictions. What head, cam combo can I use to get up to 320HP without using Edelbrock Aluminum heads or milling.
Hi, a little clarification on hp numbers. Prior to 1972 hp and torque numbers were measured at the crankshaft with just the bare engine. Beginning in 1972 all hp and torque ratings were measured at the back of the transmission with all options in and operating. These are called SAE net ratings. This caused all hp and torque ratings to drop 60 to 80 hp for a virtually identicle engine as was available in 71. The killer for horsepower and torque actually came in 71 when it was federally mandated that all engines produced be able to run on regular fuel so thus the big compression ratio drop that year. So this said a 71 400 with 300 hp changed to a 220 hp engine in 72 with no real changes to the engine. With these changes a 68 400 making 350 hp in sae net ratings would be closer to 280 hp. So with your engine do you want to add 60 hp or 130 hp?
Don't forget the high HP motors up though 70 (or 71) used high compression which required leaded high octane fuel. High compression was the result of small chamber heads. It's tougher to achieve high horsepower these days with crappy 93 octane unleaded. It takes some finesse.
Well, I typed (the hunt & peck system) for about 20 + minutes, then hit the backspace bar and my entire post disappeared.
So, I'm gonna start over and this time just make several short posts.
Howdy ya'll ! I'm new here but I been on the planet for a while.
I wuz readin this thread and thought I'd like to chime in, if it's OK.
1st, I noticed that the OP said he can't afford $2400 for alum heads. So, that begs the question : What is your TOTAL budget for the ENTIRE engine ?
This will dictate what parts and machine work you can afford. For example: if the total budget is $3000 or less, you'll probably have to use the #17 heads, cast rods, cast pistons, and a Summit cam kit.
I'll end this post with a crate 400, which will make over 350 hp. It'll cost around $4000 or just a tad over with shipping. And for a couple of hundred more, you can probably get forged rods. This is just to give you an idea of what a good crate motor, similar to what you want, will cost.
Well, this will be the 3rd time I've tried to post on this thread. This time I'll copy it before submitting, so that if it don't go thru, I won't have to type (the 2-finger hunt & peck system) it again. This is my 1st day here, so ya'll bear with me, please. I'll get the hang of it.
OK, the OP stated that he didn't have $2400 to spend on alum heads. So, that begs the question, what is your TOTAL budget ?
That will determine what parts and machine work you can afford. For example: if $3000 is your total budget, then you will probably be limited to the #17 heads you have, cast pistons, cast rods, and a Summit cam kit. The amount you can spend on upgrading the heads will depend on what the rest of the build costs. It will be best to get new stainless steel valves, hardened seat inserts and a GOOD 3-angle valve job, with new guides and seals, as well as having screw-in studs installed. But, if there is not $ for all that, you'll have to make do with less.
Just to give you an idea of what stuff costs, here is a 350 + hp, 400 longblock crate engine. It will run just over $4000 shipped. For a couple of hundred more you can probably get forged rods too.
Here's another item to consider. For the price of having studs and hardened seats installed in the #17 heads, you can buy a good set of 6x-4 head cores. These already have screw-in studs, hardened seats and 2.11 intake valves. Then, the $ you get from the sale of the #64 heads will go along way to doing a GOOD valve job on the 6x heads. About all they need is some SS valves, guides, and seals. Then just a reasonable cut to get around 90cc chambers.
Then zero deck the block (or no more than .005 in the hole), with SP L2262F + 030 forged pistons and 5140 RPM forged rods, if your budget will allow.
Then, to bring the SCR & DCR up a little, buy Cometic .036 x 4.160 head gaskets, and run a Voodoo 262 cam. This combo should be pump gas friendly and make well over 300hp.
I'll plug in the numbers from my last post and see what we come up with.
400 + .030 bore, 90cc chambers, 6.7cc valve reliefs, .036 x 4.160 Cometic head gaskets, and .005 deck height CR = 8.86
So, this combo with either the 262 or 256 Voodoo cam should make well over 300hp AND be pump gas friendly.
This engine combo with the 262 cam and a stall converter with a TRUE stall speed of 2600, and the lower 1st gear ratio of the 2004R tranny, should make for a spunky launch, or a lot of tire smoke, depending on traction.
For another couple of hundred bucks or so, you can go with lighter, Auto-Tec brand pistons and H-beam rods. This will make the rotating assembly lighter, which will free up some hp, and allow the engine to turn higher rpm safely. The valve relief volume is lower, @ 3.8cc , since they have only 2, instead four, as on the SP pistons. So that will increase CR slightly, also.
That's a good deal on the Len Williams engines. Not sure I could build one of my cores for that anymore. Good machine cost more. And get'n harder to find. Last good guy machinest 1/2 hour from me retired. Will have drive 1-1.5 hr from here now.