BBC rollers on 4.0 head

[xdark]

I know theres alot of debate on this but i believe with the right application there is real benefit. Also swaping stock cam soon that will see 5500 plus rpms. I do have magnum guide plates that look like they will work. Im looking more at 3/8 over 5/16 studs . 7120 head that is already ported and polished. Anyone have hands on experience with this swap? I love the HS rollers just dont like they are stock stud size.

[jsawduste]

The towers are know to break when fitted out for 3/8th's studs

[xdark]

For all head castings?

[jsawduste]

7120`s I know, suspect all. FWIW the Edlebrock has larger towers just for this purpose/reason.

Perhaps Pottenger may chime in but I think you already know the answer.

[xdark]

Ever heard of HS studs bending or breaking ? Because if 5/16th is the better option then might as well go HS or yella.

[xdark]

As much as i would love to go with a edelbrock or hesco head my wallet dont agree lol but i didn't know edelbrock valve stud towers were oversized . i like that .

[jsawduste]

Little known fact away from this forum but both aluminum heads are duds. Even when well massaged a good 7120/0630 will out flow them A heads. Yes the A's are lighter and the E head has a better chamber but the ROI sucks.
If your keeping the typical accepted spring rates the 5/16's should work fine.
HS makes a 1:7 BTW. Contact Pottenger for them.
Crane I believe has a 5/16's thread and a 3/8's shank FWIW.

[SIXPAK]

Little known fact away from this forum but both aluminum heads are duds. Even when well massaged a good 7120/0630 will out flow them A heads. Yes the A's are lighter and the E head has a better chamber but the ROI sucks.
If your keeping the typical accepted spring rates the 5/16's should work fine.
HS makes a 1:7 BTW. Contact Pottenger for them.
Crane I believe has a 5/16's thread and a 3/8's shank FWIW.

I dont agree on the Alm. heads being duds. I would definately go for the Edelbrock over the Hesco though. I know of a cast 7120 that flows over the 300cfm mark but that is with a LOT of work, some VERY unique things were done to it. Russ has already ported the Eddy to 300+

[Russ Pottenger]

Little known fact away from this forum but both aluminum heads are duds. Even when well massaged a good 7120/0630 will out flow them A heads. Yes the A's are lighter and the E head has a better chamber but the ROI sucks.
If your keeping the typical accepted spring rates the 5/16's should work fine.
HS makes a 1:7 BTW. Contact Pottenger for them.
Crane I believe has a 5/16's thread and a 3/8's shank FWIW.

Not much that I add to what John has said.
We've been successively running valve springs with spring rates
anywhere between 25 to 35lbs and nose pressure at or just below 300lbs without any problems or issues.

I'm a Harland Sharp dealer and stock both adjustable and nonadjustable roller rockers
in 1.6 and 1.7 ratios.

I see no reason to deviate from this reliable combination.
Don't hesitate to contact me if I can help you in anyway with products and pricing.


Russ

[CandyCaneXj]

I had the HS non adjustable 5/16 rockers on my 4.0 for 8,000 miles and would redline it quite a bit with a 1990 cam and springs and they never broke or came loose. Didn't use thread locker either. When I took them out later the bolts came out nice and easy and showed no signs of stretch. The allen heads are a strip waiting to happen though. I agree that 3/8 is too big for the thin towers. Plus the threads are not even centered on them. I think the aluminum heads are a joke all that money and they still could use porting!! It's all for money these manufactures say it works with a stock 4.0 or a stroker. If it is made to work on a 4.0 then you know it's going to restrict power on a stroker. Edelbrock's head is 144 cc intake and 77 cc exhaust and it says max lift is only .540. That's junk. If you put a head with that size runners or flow numbers on a chevy 350 or 383 stroker(roughly same displacement per cylinder as a jeep 4.6, 4.7, 4.8) you would be laughed at. Best off getting a cheap used head and having it done right.

[xdark]

On paper the aluminum heads look good but have no real world experience with them . i did a port and polish on my 7120 head and definitely felt a difference at higher rpms . so far I am leaning more for the HS rollers non adjustable I just wanted to really see what my options were as i do know if i did go with BBC rollers in the end would cost the same if not more than the HS and more work to my head .Russ have you ever installed BBC rollers on a 4.0 head?

[jsawduste]

Little known fact away from this forum but both aluminum heads are duds. Even when well massaged a good 7120/0630 will out flow them A heads. Yes the A's are lighter and the E head has a better chamber but the ROI sucks.
If your keeping the typical accepted spring rates the 5/16's should work fine.
HS makes a 1:7 BTW. Contact Pottenger for them.
Crane I believe has a 5/16's thread and a 3/8's shank FWIW.

Not much that I add to what John has said.
We've been successively running valve springs with spring rates
anywhere between 25 to 35lbs and nose pressure at or just below 300lbs without any problems or issues.

I'm a Harland Sharp dealer and stock both adjustable and nonadjustable roller rockers
in 1.6 and 1.7 ratios.

I see no reason to deviate from this reliable combination.
Don't hesitate to contact me if I can help you in anyway with products and pricing.


Russ

Thanks Russ.