[Mike S]

Thinking of changing from my old 72cc e-heads that flow 330 to a set of high ports with 80cc chambers to lower compression a little. Fron 11.5 to 10.8. Want to be safe for pump gas.
Will the e-head head studs work on the high port heads? will the e-head stud girdle work? How about pushrod length? Any other changes am I looking at. Are the exhaust ports raised?

Has anyone made the change from e-heads to high ports?

[Bill Eveland]

I ended up going the opposite way even though now the edelbrocks are for sale already lol.

Studs and girdles are different. With my crower ss rockers, My highports needed a 10.4" pushrod where as my Edelbrocks needed a 9.2 i believe. That was with lash caps . Pay close attention to rocker to spring retainer clearance, the lash caps help some, and pushrod to rocker arm under a lift event. Exhaust is the same.

[Dragncar]

Well, I run 80cc High Ports that were going to give me 10.8 CR and milled them (.030 ?) to get the CR UP TO 11.5 to run pump gas. 74 ccs now.
Its sort of pump gas right now. 1/2 gallon of 112 to 4 1/2 gal of 91 to get me 93 octane which is pump gas in some areas. I don't think I will ever go down to 91 octane. I have a bunch of all gas 92, think I will end up there.
A little bowl work and those High Ports can get to just about 360cfm. .800 lift but still flow 350cfm where you can use it around .700
Remember, High Ports like lift.

[mysticmissle]

Originally Posted by Mike S

Thinking of changing from my old 72cc e-heads that flow 330 to a set of high ports with 80cc chambers to lower compression a little. Fron 11.5 to 10.8. Want to be safe for pump gas.
Will the e-head head studs work on the high port heads? will the e-head stud girdle work? How about pushrod length? Any other changes am I looking at. Are the exhaust ports raised?

Has anyone made the change from e-heads to high ports?

as Bill said except for the rockers, the girdel, studs, pushrods will all require extra length, you may be able to reuse the shorter studs and piece together the longer 6/ head but really no savings. And yes, depending on your headers, they may hit in different areas, as the exhaust ports do rise by about .375'' if i recall. not a huge deal, but something to be aware of.

[Elarson]

Originally Posted by mysticmissle

as Bill said except for the rockers, the girdel, studs, pushrods will all require extra length, you may be able to reuse the shorter studs and piece together the longer 6/ head but really no savings. And yes, depending on your headers, they may hit in different areas, as the exhaust ports do rise by about .375'' if i recall. not a huge deal, but something to be aware of.

Yes, and the rise of the exhaust ports pushes them outboard too. My headers hit the steering shaft at the big joint, so I had to get an aftermarket steering shaft with smaller diameter joints.

And remember that one of the accessory bolt holes at the end of the head is missing. Jeff says it's too close to their water jacket to tap the missing hole.

Eric

[Mike S]

Thanks guys.
Just trying to come up with a plan for lower compression. Right now I have 11.5 and have been 6.04 in the 1/8, so heads work. Want to get it just under 11.
Thinking about polishing the cambers and unshrouding the intake valve a hair and see where that puts me.

[slowbird]

The girdle isn't the same? I would think it would be the same. If the shaft rockers are interchangeable why wouldn't the stud girdle be also?

[mysticmissle]

Shaft rockers swap 380plus hi ports to e head wide ports
I believe even the 330 hi ports have the valves moved a little bit

[mysticmissle]

Originally Posted by Mike S

Thanks guys.
Just trying to come up with a plan for lower compression. Right now I have 11.5 and have been 6.04 in the 1/8, so heads work. Want to get it just under 11.
Thinking about polishing the cambers and unshrouding the intake valve a hair and see where that puts me.

Why not just smooth the chamber and soften some
Radius I bet you get where you are safe

[Dragncar]

Originally Posted by slowbird

The girdle isn't the same? I would think it would be the same. If the shaft rockers are interchangeable why wouldn't the stud girdle be also?

Because there is a slight difference between the shaft rocker setups but they are still close enough to center on top of the valve stem to work.
At least that is how i understand it.
But with a stud, there is not room for any misalignment, has to be exact.

[slowbird]

Originally Posted by Dragncar

Because there is a slight difference between the shaft rocker setups but they are still close enough to center on top of the valve stem to work.
At least that is how i understand it.
But with a stud, there is not room for any misalignment, has to be exact.

I disagree. The shaft rockers bar mounts to the stud holes and it mounts just fine. I have swapped shaft rockers from hp to eheads multiple times without issue. But maybe there is something I'm missing with the girdle.

[Bill Eveland]

well I'm using my fenderwell headers I built and didn't notice any change. I thought I read even on kres page it was the same. They even lists seperate stud girdle for Highports, d ports and Edelbrocks

[slowbird]

Originally Posted by Bill Eveland

well I'm using my fenderwell headers I built and didn't notice any change. I thought I read even on kres page it was the same. They even lists seperate stud girdle for Highports, d ports and Edelbrocks

D-ports are different from eheads as the valve spacing is different between the two but ehead round ports and hp heads have same valve spacing at least the last I knew they did.

[ponjohn]

Curious:

Are the runners the same volume?

I've read several engine builders say the reserve the HP for larger cubic inches.

[Steve C.]

It is my understanding the HP as cast port is 277cc's.

Also keep in mind the spring pressure with the larger 2.20 intake valve.
Also the valve length is 6.200" and the installed height is around 2.000"

This was my info obtained in 2005. I presume it is still similar.

.

[GOAT8U2]

Any chance you can get E85 at a pump near you?
8 gallons of 93 w 2 gals of E80 (most pumps aren't close to E85) etc is 95 octane and not a big change in AFR, E20 pretty much.

[Dragncar]

Originally Posted by slowbird

I disagree. The shaft rockers bar mounts to the stud holes and it mounts just fine. I have swapped shaft rockers from hp to eheads multiple times without issue. But maybe there is something I'm missing with the girdle.

Maybe you are right.
Could the stud/bolt holes in the 2 heads be the same but the valves in the heads are moved some ?

[Dave Polichena]

Originally Posted by Dragncar

Maybe you are right.
Could the stud/bolt holes in the 2 heads be the same but the valves in the heads are moved some ?

This is correct, the stud girdle will work for either head.