Rocker arms for 408 build

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Read all 4 parts @ B3 racing.
It is a lot easier than explaining and retyping it to you.

B3 Racing Engines LLC - Mopar Rocker Arm Geometry Tech
Thanks Rob. Read all that a while back, been in contact with Mike.
No answers to be had for Magnum heads.
I spoke to PRW today, they minimize any concern about weakness without a girdle with my setup at about 300 lb open. Also found they likely to not fit under standard valve covers.
I have seen a report that the HS setup great with no shims on an RHS head so perhaps the lack of fulcrum height adjustability is a non issue, stronger, more stable.
One irritant, I see no reasonably priced tall valve covers for a magnum so I lean toward the nonadjustable HS.
 
Then use regular LA covers on the Magnum.
But I’d like to score a set of the black wrinkle MP “MAGNUM” covers myself!
 
I did not know that was possible. Google shows it works. Thanks.
Still debating which rockers.
 
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Idaho, I have EQ magnum heads on my 408 and am using the HS rockers but the adjustable ones. Geometry was very close. I wouldn't say perfect but close. Just thought I'd let you know my experience with them
 
Idaho, I have EQ magnum heads on my 408 and am using the HS rockers but the adjustable ones. Geometry was very close. I wouldn't say perfect but close. Just thought I'd let you know my experience with them

Thanks for that. I'm not sure if it was you who posted that experience before. If not that makes two.
I do like their design.
What valve covers are you using?
 
I will be glad to share my experience.
1 thing. I was using stock magnum heads. We cut the seats for 1.97 RT valves and I had Hughes .500 lift Single springs with 2.2 retainers. I was using a Hughes custom hydraulic cam with a .300 base circle. When all said and done I was at about .480 lift. I was racing oval dirt 1/4 mile where the rules said factory only on the valve train except screw in studs and guide plates were allowed. I used 3/8 MP fulcrums that I cut 1/2 the platform off with a hi speed cutting wheel on a die grinder. I used the 5/16 x 3 8 studs from the Comp Cams kit along with the guide plates. I used the MP push-rods made for the conversion. (7.165 I think was the length)? I also had to take some material off the stud close to the bottom because the fulcrum would go down to far and get tight. I then used Stock rockers with poly locks and the the adjustment was 1/2 turn from zero lash. I ran this set up for 15-20 race nights at 6500 RPM lap after lap. I broke a fulcrum in half but never noticed a running difference. We found it doing a manifold swap when the rules changed for the next year..
The along with "any factory" manifold rule change it was also changed that "stock style" rockers could be used. I then went to a custom length hardened push-rod and the Summit Brand 1.6 Chevy rocker. At that time I began to converse with Joey Case from Dallas GA. He advised me to run the lifters preloaded at .120 deep.
I never had a geometry problem that was out of this world.
 
I will be glad to share my experience.
1 thing. I was using stock magnum heads. We cut the seats for 1.97 RT valves and I had Hughes .500 lift Single springs with 2.2 retainers. I was using a Hughes custom hydraulic cam with a .300 base circle. When all said and done I was at about .480 lift. I was racing oval dirt 1/4 mile where the rules said factory only on the valve train except screw in studs and guide plates were allowed. I used 3/8 MP fulcrums that I cut 1/2 the platform off with a hi speed cutting wheel on a die grinder. I used the 5/16 x 3 8 studs from the Comp Cams kit along with the guide plates. I used the MP push-rods made for the conversion. (7.165 I think was the length)? I also had to take some material off the stud close to the bottom because the fulcrum would go down to far and get tight. I then used Stock rockers with poly locks and the the adjustment was 1/2 turn from zero lash. I ran this set up for 15-20 race nights at 6500 RPM lap after lap. I broke a fulcrum in half but never noticed a running difference. We found it doing a manifold swap when the rules changed for the next year..
The along with "any factory" manifold rule change it was also changed that "stock style" rockers could be used. I then went to a custom length hardened push-rod and the Summit Brand 1.6 Chevy rocker. At that time I began to converse with Joey Case from Dallas GA. He advised me to run the lifters preloaded at .120 deep.
I never had a geometry problem that was out of this world.

That's some interesting stuff. I'm having trouble understanding how stock rockers are used with a non-stock fulcrum and poly locks.

525v lift stock rockers work fine

That had been my understanding. When I looked at what was happening with .515 lift I did not like the look. With that and my .020 variability in valve height I decided to bite the bullet and order adjustable HS rockers.
If nothing else I will have peace of mind. If I had not done the stroker, I think I'd have tried the stock rockers. Too much invested now.
 
That's some interesting stuff. I'm having trouble understanding how stock rockers are used with a non-stock fulcrum and poly locks.

The fulcrum was a MP piece made for magnum engines. I cut the bottom off so it would not bottom off on the screw in studs. The poly lock served as the lock nut. Not sure how else to explain it. I do still have them.


That had been my understanding. When I looked at what was happening with .515 lift I did not like the look. With that and my .020 variability in valve height I decided to bite the bullet and order adjustable HS rockers.
If nothing else I will have peace of mind. If I had not done the stroker, I think I'd have tried the stock rockers. Too much invested now.
 
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Stock rockers are fine. All those old super stocks in the 60's ran the hell outta them. You won't have any issues.
 
Stock rockers are fine. All those old super stocks in the 60's ran the hell outta them. You won't have any issues.
No pedestals in the 60s right?
I think you are referring to the LA style shaft rockers.
 
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