C9OE-E small chamber heads help.

[cyclone460]

I'm told these are great 1 year only heads and I have a chance to get them. 1 rocker stud is pulled and I plan on replacing all with screw in studs. These heads are ready to run so I don't want to take to a machine shop to mill .240 off the mount to use the studs with the hex at the base. Those studs that I see don't work with OE rockers either. My problem is, I google this and I can't find the Ford tool that removes the press in stud and taps for screw in studs. I see them for brand x at Jegs and Summit but not for SB Ford. I also can't find the straight (non hex at base) screw in studs. Any help or other ideas would be appreciated.

[Rocket989]

I thought the J-code 302 head was '68... C8OE... Could be wrong though!! I've never heard of screw-in studs w/o a hex base; how would you torque 'em?!? Also, yah...milling the rocker bosses keeps geometry in line. You want to keep the OEM rail rockers? If you can keep the same spacing, they oughtta work.

I'll do a little digging in a few old Ford perf parts books I've got and will post back.

[cyclone460]

I thought the J-code 302 head was '68... C8OE... Could be wrong though!! I've never heard of screw-in studs w/o a hex base; how would you torque 'em?!? Also, yah...milling the rocker bosses keeps geometry in line. You want to keep the OEM rail rockers? If you can keep the same spacing, they oughtta work.

I'll do a little digging in a few old Ford perf parts books I've got and will post back.

Thanks! I saw a video on youtube university and they did what I'm talking about on a cheby. I could use the hex base stud but, without milling, I would have to get longer push rods. To torque the non hex , you use a poly lock or double nut. yes, I would like to keep the oem rockers.

[Rocket989]

I was thinking about this and if you don't want to pay a machine shop to mill the rocker bosses and drill/ tap for screw-in studs, I'd get the one stud replaced (use bushings and a brass hammer to WHACK it in) and pin them. The press-in studs are 3/8 thread AND 3/8 knurl so they'll have to be drilled and tapped (for screw-in studs, Ford and probably others almost all use a 7/16-14 thread for the part of the stud that screws in the head).

If you do go with a screw-in type, at a minimum I'd use a drill press...having 'em anything but straight is not good! I checked the stuff I've got including the FOORRDD Performance guide (an awesome reference) and didn't see a puller/ alignment tool for SBF heads..I know which ones you're talking about for the Chebbie stuff...I don't know if the spacing is different!!

Looks like Mr. Gasket sells a set of studs that don't use a hex base:
https://www.summitracing.com/parts/mrg- ... aQodIV0I2Q

Also, rail rockers aren't great for high lift cams, so anything more than mild I wouldn't run 'em!!

[cyclone460]

Thank you for that info !! Now I have something to think about!

[StPro]

I was thinking about this and if you don't want to pay a machine shop to mill the rocker bosses and drill/ tap for screw-in studs, I'd get the one stud replaced (use bushings and a brass hammer to WHACK it in) and pin them. The press-in studs are 3/8 thread AND 3/8 knurl so they'll have to be drilled and tapped (for screw-in studs, Ford and probably others almost all use a 7/16-14 thread for the part of the stud that screws in the head).

If you do go with a screw-in type, at a minimum I'd use a drill press...having 'em anything but straight is not good! I checked the stuff I've got including the FOORRDD Performance guide (an awesome reference) and didn't see a puller/ alignment tool for SBF heads..I know which ones you're talking about for the Chebbie stuff...I don't know if the spacing is different!!

]

I am with Rocket. Press in a stud and pin it with a roll pin unless your going high lift high RPM. If you want to rev the motor have it done at a machine shop. Money well spent

[cyclone460]

I was thinking about this and if you don't want to pay a machine shop to mill the rocker bosses and drill/ tap for screw-in studs, I'd get the one stud replaced (use bushings and a brass hammer to WHACK it in) and pin them. The press-in studs are 3/8 thread AND 3/8 knurl so they'll have to be drilled and tapped (for screw-in studs, Ford and probably others almost all use a 7/16-14 thread for the part of the stud that screws in the head).

If you do go with a screw-in type, at a minimum I'd use a drill press...having 'em anything but straight is not good! I checked the stuff I've got including the FOORRDD Performance guide (an awesome reference) and didn't see a puller/ alignment tool for SBF heads..I know which ones you're talking about for the Chebbie stuff...I don't know if the spacing is different!!

]

I am with Rocket. Press in a stud and pin it with a roll pin unless your going high lift high RPM. If you want to rev the motor have it done at a machine shop. Money well spent

I think both of you are right. Ya never know, I might want to go with a thumper cam down the road. Should I go with push rod guide plates in case I go roller rockers also? Thanks!

[Rocket989]

You'll have to...the rail rockers keep the pushrods aligned. Without 'em you gotta have something to keep them aligned. Though if you do that, you'll need the hex studs to lock the guide plates down. Comp Cams (and maybe others) make a roller-tipped rail rocker.

If you go beyond pinned studs and a rail-type rocker, might as well get the machine work done!! I forget at what lift (close to .500 maybe?) you have to watch close...the ears of the rail rockers can start pushing down on the retainers...if it's far enough, the locks can slip. Poof!! You drop a valve...

[cyclone460]

From what I read about specs, the c9oe-e heads are 58.2 cc 1.78 int. 1.45 exh. my c6oe heads are 54cc 1.67 int. 1.45 exh. and need a valve job and screw in studs. the c9oe heads are for sale for $100.00 with the valve job done but needs screw in studs. My dilemma is which way to go.Are the c9oe heads better or worse choice. Should I just do my c6oe heads? thanks!

[Rocket989]

What are the heads going on?

[cyclone460]

A stock 1966 289 edelbrock intake holley 650 four barrel auto trans.

[Rocket989]

Yea...a lot of later 289 heads allegedly came with 1.78 intake valves...I haven't seen too many of 'em! I've got one set of C6OE heads left; I forget - will have to measure the intake valves.

4cc will drop compression about a half-point. On a 4V engine that's better than a 2V engine... The 1.585 compression height pistons on the latter (and assuming about .020 in the hole and a .047 compressed gasket) is going to closer to 8.5:1 vs 9:1 static.

If your running 1.605 CH pistons, it'll be more like 9:1 or a little higher (with the larger CC heads). With a stock or small cam, any of 'em are probably OK. With a bigger stick, I'd want at least 9:5.1.

You can always have a machine shop replace the 1 press-in stud in the C9 heads and mill 'em .020. Probably cheaper than a full redo on the C6's. Then drill/ pin your studs and use whatever rail rockers.

[cyclone460]

Yea...a lot of later 289 heads allegedly came with 1.78 intake valves...I haven't seen too many of 'em! I've got one set of C6OE heads left; I forget - will have to measure the intake valves.

4cc will drop compression about a half-point. On a 4V engine that's better than a 2V engine... The 1.585 compression height pistons on the latter (and assuming about .020 in the hole and a .047 compressed gasket) is going to closer to 8.5:1 vs 9:1 static.

If your running 1.605 CH pistons, it'll be more like 9:1 or a little higher (with the larger CC heads). With a stock or small cam, any of 'em are probably OK. With a bigger stick, I'd want at least 9:5.1.

You can always have a machine shop replace the 1 press-in stud in the C9 heads and mill 'em .020. Probably cheaper than a full redo on the C6's. Then drill/ pin your studs and use whatever rail rockers.

Thanks for that very important info! I don't know the CH on the 289 but I left to get those heads before I read your post. It turns out the heads are ported on the intake and exhaust.(bumps removed) valves were left stock for low end torque. positive stop valve stem seals and valve springs for up to .550 lift. I hope you don't think I'm being a pain and you may think I'm nuts but after reading your post about compression ratio, I may have another alternative and I would value your input. I have a completely rebuilt 1971 302 2bbl that I was going to put in my wife's 66 mustang convertible that needs a total restore. From what I read, this 71 302 has the 9.5:1 CR that is needed for a thumper cam. I'm thinking I could use the C9Oe heads I just picked up, on this motor after I take them to the machine shop for screw in studs and get roller rockers w/ guide plates and put it in my 65 comet. I also would use a 1969 c4 trans. 157 tooth 26 spline i/o because my merc o matic does the 2-3 slip. what are your thoughts? Thanks for letting me pick your brain!

[Rocket989]

Sorry, lost me - the C9 302 heads or the C6 289 heads have been worked as described??

I think the Thumpr cams are great...flat tappet or hydro roller, they get beat up by experts, but I don't know anyone with one installed that ain't happy! And if nothing else the TIGHT LS is good for small valve, iron heads.

You do want compression though. Low cylinder pressure = turd unless it's wailing!

[cyclone460]

The C9Oe heads that I just picked up have the porting , positive stop seals and .550 valve springs. Thanks