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I am doing a rebuild on a 351 w in a 85 ford f-150 I am trying to decide if I should spend the extra dollars on keith black hypereutectic pistons which will raise comp. from 9.2 to 9.8 or take the money saved and spend it on a comp cam extreme energy cam instead of the rv cam that comes in the rebuild kit. Other mods are headers and performer rpm intake, 600 cfm holley.
What would you do

<font size=-1>[ This Message was edited by: Chad on 12/27/01 11:16pm ]</font>
 

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Personally, I'd do the cam change. I'd say the XE256 for your truck. It really depends on the rest of your setup though (heads, valvetrain, etc). I ran the XE262H in my 351w mustang with the RPM intake and an Edelbrock 600 carb. With 2.79 gears and a stock converter I still had a ton of bottom and mid-range with a decent top-end that would rev to 6000 no prob. My comp ratio was 9.5:1, your 9.2:1 should be just fine. I don't think you'd see much of a difference, if any at all, going from 9.2 to 9.8 compression with an RV cam. You'd also need to make sure your valvetrain is up to the task of a bigger cam. If you have stock heads you will probably need to replace the pressed rocker arm studs, I tried a bigger cam with my stock heads and had one come out almost right away as soon as I got the RPM's up.

Brock
 

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Brock
Is that the cam they list for the 4X4's. Did you have to go to screw in studs and guideplates? I really wasn't wanting to spend that much on the heads.

<font size=-1>[ This Message was edited by: Chad on 12/28/01 2:19am ]</font>
 

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Hey Chad,

If you want to raise the compression ratio without having to buy new pistons look for a thinner head gasket. I think the regular Ultra Blue Felpro gasket compresses to about .041”. I have seen steel shim gaskets that are suppose to compress to about .015”. The ones I have seen were for the FE, but you may be able to find some for the Windsor.

Hope this helps,

Gregg
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Are you ever really finished working on them?
 

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The best HP/$ mod you could make is to pull your heads down and do some clean up of the intake and exhaust ports before you get them rebuilt. Just blending in all the ridges below the valve seat and smoothing out the short side radius plus removing the thermactor bump from off the roof of the exhaust port and opening up the exhaust port slightly can easily give 20 - 30 HP. If you can do the work yourself it's basically free, just costing you a bit of time.
 

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I was going to give them a Flow-nati home port job anyway. I should of said this at the front but this is a complete rebuild so its not like I am taking the motor apart to change the pistons.
 

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Chad, no, I was refering to the regular XE cams. Sorry, I don't have any experience with the XE 4x4 cams but the X4262H is close to the XE262H that I had. I ended up getting the World Sr. head that have screw-in studs and I do run guideplates.

My advice to you is make sure you do it right the first time or you will regret it and end up spending more money later. I figured that out first hand and now have my 351 back out of the car. The first time I built it, I cut corners mainly because of lack of time and knowledge. Now I have the motor apart and will be doing it right this time. Even though I will be spending more money than I could have, the plus side is I did gain alot of experience. If I were you I would first figure out my budget then determine what can be done within that budget while still making sure to not mis-match components or cut corners.

Good luck,
Brock
 

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Hallo Brock,
I am also building a 351 for my 67 Mustang with c4 tranny and 3.00 rear.
The cam is nearly the same(268) have the rpm intake and the 600 cfm carb.
I am interisted how many hp you get out of your combo, or do you know how my combo will work?
The heads will be ported 289 heads (54cc chambers) to get an accurate comp.
thanks for every input.
 

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Robbi, if your talking about the XE268 then I would think that you would need more gear than 3.00. Also, I don't know from experience but I have read on here that the 351 heads flow better then the 289 or 302.

I don't know the hp rating of my old setup with the 262 but I gues it was somewhere around 350hp.
 

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Thanks,

I asked only to know if I will have some fun with that engine in my mustang.
Normaly I have a 289 but it needs a complete rebuild.
I will go on the 351 with canfield heads but will buy them next year when I buy all parts I need for the 289 rebuild.
Then the ported heads come back on my 289.
 
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