Plans for 289; 1.7:1 rockers? Mill heads or not?

[streetstang67]

Ok, after much thought, I plan on doing the following things to my engine/car, (current specs are in signature):

First off, gotta add A/C, otherwise I'll end up never wanting to drive this car.

Replace performer manifold with chrome performer RPM Air Gap intake; will it fit under the hood?

Remove heads and have them ported, polished, and enlarged valves installed.

So since I'm doing all that, I'm also considering milling the heads for more compression and installing 1.7:1 rockers. Do you think either one of those things is worth the money?

So if I do all this with my current setup, do you think all the parts will match in harmony? I want everything to work together with no single component holding something else from full potential.

Thanks for the help....please help me with these last few decisions.

 

[12sec67]

i think it would be most cost efficent to get a good set of aftermarket heads then spending the money on reworking the stock ones.

 

[iskwezm]

dont waste the money on stock heads,you probably spend close to 700 bucks or more on labor,valves and new springs.New heads can be found used for the same price or new for a little bit more.Aslo dont mill your heads and run 1.7 rockers,unless your cam is small and there valve to piston contact.You can run the rpm air gap,but have to use a 2 inch air cleaner.

 

[streetstang67]

While I decide about the heads...my cam is XE256H (.477 and .484 lift). Knowing that, would you suggest milling the heads, 1.7:1 rockers, both, or neither? Also, how does the performer RPM compare to the Air Gap?

 

[Britt]

First thing you should do is get a shift kit in that tranny.

Look into thumper heads. They are E-7s that he ports, polishes and i think he even does a 5 angle valve job on for around 600 bucks.

The RPM is fine.

Next I would get a bigger cam and a higher stalling converter, but this is isnt really a necesity until you want more power.

 

[iskwezm]

The RPM air gap is the same manifold as the RPM,just has open plenum to cool the runners.The problem with milling the heads is one you mill them,if you go to a bigger cam later,you need to watch your clearances with too much lift.I have seen Edelbrock heads many a time for 700-1000 bucks new and used.I have them, but out of the box,they will drop your compression due to the 60cc chambers.I also had mine ported hich made a big difference and run 1.6 rockers.My cam now is a 576/596 lift and 244/254 duration at .050.I dont know how it sounds yet,the motor should be done this week.Yor cam is kinda small to benefit from higher compression,but the rockers would help,make it act like its bigger.

 

[rbohm]

i would NOT use 1.7 rockers unless you plan on upgrading your valve springs. the higher ratio rockers put much more pressure on the springs and they tend to fail sooner, unless you plan for them in advance. also what is your plan for this engine, daily driver, toy, race motor? each has different requirements and needs to be tended to differently. it sounds to me like you are building a daily driver, in which case the cam you selected is just fine, and use good 1.6 rockers.

oh and mill the heads just the amount needed to make them flat, otherwise you end up haveing to mill the intake also, and the compression increase isnt worth the effort. rememeber as you increase compression, the likelyhood of needed higher octane fuel increases.

 

[D.Hearne]

I second the motion to not invest all that money in stock heads, good aftermarket heads will cost you just as much. As for 1.6 vs 1.7 rockers, the 1.7's only net you .030 more lift, not enough to have to worry about piston contact with that cam. I'm running 1.7's on a set of milled (by .060) Canfield heads with a Ford Racing Z303 cam ( lift is now .587) and have no problems with piston to valve contact. Hasn't hurt the springs either.