Help me run on pump gas.

69F100 wrote:You could get a new set of dish piston to lower the c/r they may have to custom made might check. With  prob piston they may have a set or make you a set.

supervel45 wrote:http://www.wallaceracing.com/dynamic-cr.php   You can run your cam spec.s through here and see what the dymanic compression will be. You can also retard the cam to lower it. Like Randy said it will be a compromise with the high compression and low octane. I would use the D3 heads myself. You get to do away with the rail rockers and get hardened exhaust seats as a bonus. The compression ratio will be in the mid 9 range and with your cam at 0 or advanced slightly, and more ignition timing, should make more low end power, where you need it with a heavy car.

69F100 wrote:You could get a new set of dish piston to lower the c/r they may have to custom made might check. With  prob piston they may have a set or make you a set.

rmcomprandy wrote:Any "crutch" you use to simply be able to run pump gas would cost power.
Changing the heads to something like the D2OE-AB Police Interceptor heads would be the best thing to do, if you are set on keeping it a 429.

supervel45 wrote:https://www.fordmuscle.com/archives/2004/05/EdelbrockFlowTest/index.php   If you want to spend the money, the Edelbrock's are nice. They kind of copied the PI intake ports, and made the exhaust ports to fit regular headers, so that's a plus along with the weight savings. You will need roller rockers and hardened pushrods also.

supervel45 wrote:If you go with the Edelbrocks, you may also want to get their headbolt kit, as they are different than stock oem. Some people use the stock bolts, but it is harder to get a socket on them. Now you have to decide between the 75cc and the 95cc chambers, since they are aluminum and you can get by with more compression. If you don't like paying for super all the time, go with the 95's.

supervel45 wrote:The way I see it, is if I am going to lay out the money for aluminum heads and everything that goes with them, I would want the best bang for my buck.  This would include a bigger camshaft than the Comp 268 you have, along with a higher stall convertor and matching rear end gears, exhaust, ect. On a 429 with high dollar heads and valvetrain, I would cam it for at least 6,500 RPM's. I would go for something like the Xtreme Energy 274, or even the Edelbrock matching RPM cam, or a custom grind and would also seriously consider a solid or mechanical roller. The 268 you have makes alot more sense with the D3's and a stock torque convertor and high gears in a budget build than with the Edelbrocks in that combination to me. What I am saying is there is no way I would use your cam with the Edelbrocks' with 75cc or 95cc chambers, regardless or detonation or gas costs. Think of it this way, $1K headers, $2.5K to $3K heads intake roller rokers pushrods ect. 5,500RPM or so peak HP, and almost zero ( or if it's even 50 HP ) gain over a well ported set D3's does not add up to good to me. Here is another thing to consider, you said want to stick with 429 CID, and I believe you mentioned porting the iron heads yourself, nothing wrong with that, it makes pefect sense with your 268 cam. You should consider this, you could by a stroker kit with the money saved from the  aluminum heads and other required related parts and make more H/P and torque down low, where you need it for about the same price as the Edelbrock's with better rods and pistons and a forged crankshaft with ported D3's. I am also a die hard 429 fan, but they have their limitations, they are meant for high RPM use for best performance.

rmcomprandy wrote:A compression ratio of 10.5/1 would work fine with an aluminum head having minimal quench clearance and a cam of about 224 @.050" or larger.

supervel45 wrote:The way I see it, is if I am going to lay out the money for aluminum heads and everything that goes with them, I would want the best bang for my buck.  This would include a bigger camshaft than the Comp 268 you have, along with a higher stall convertor and matching rear end gears, exhaust, ect. On a 429 with high dollar heads and valvetrain, I would cam it for at least 6,500 RPM's. I would go for something like the Xtreme Energy 274, or even the Edelbrock matching RPM cam, or a custom grind and would also seriously consider a solid or mechanical roller. The 268 you have makes alot more sense with the D3's and a stock torque convertor and high gears in a budget build than with the Edelbrocks in that combination to me. What I am saying is there is no way I would use your cam with the Edelbrocks' with 75cc or 95cc chambers, regardless or detonation or gas costs. Think of it this way, $1K headers, $2.5K to $3K heads intake roller rokers pushrods ect. 5,500RPM or so peak HP, and almost zero ( or if it's even 50 HP ) gain over a well ported set D3's does not add up to good to me. Here is another thing to consider, you said want to stick with 429 CID, and I believe you mentioned porting the iron heads yourself, nothing wrong with that, it makes pefect sense with your 268 cam. You should consider this, you could by a stroker kit with the money saved from the  aluminum heads and other required related parts and make more H/P and torque down low, where you need it for about the same price as the Edelbrocks with better rods and pistons and a forged crankshaft with ported D3's. I am also a die hard 429 fan, but they have their limitations, they are ment for high RPM use for best performance.