Roller rockers in a 3.1 Aluminum head?

[trotterlg]

I've got some adjustable rocker studs now, I understand that the 3.1 heads need to have a "narrow body" roller rocker arm for them to function. What is the measurement in inches of "narrow"? What width do I need to get to before they won't hit things? Looks like with teh cam I have I will be running 1.5's. Which part of the rocker arm is the critical dimension? Larry

[geoffinbc]

The width of the trunnion is critical. Crane Cams sells a kit with the correct studs to fit a 60 Degree V6. 25750-12 is 1.5 ratio.

[trotterlg]

Those are the arms and studs for an inline valve head, the studs are shorter than the ones in the aluminum heads with push rod guides, those heads need ARP Rocker Arm Studs 100-7201, they match the dimensions of the origional non adjustable studs. I was wondering about how wide the rockers could be in the angle valve heads. Larry

[geoffinbc]

They work. Trust me I have installed Crane rockers on a Gen I II and III engines using their studs. Cranes old site use to list the trunnion width. The Chevy power manual also lists it.

[trotterlg]

Yes I almost bought some, but, with the pushrod guides on, they are about .100 short of what was in there, there would still be plenty of threads, but the ARP Rocker Arm Studs 100-7201 studs are exactly the same length on the bottom and are the same length as the tops minus the unthreaded part that is on the very top of the stock non adjustable studs. I ordered up a set of roler tip steel SBC Chevy rockers, I am sure they will not hit anythng, I'll have to figure out what length push rods to get when I get the rockers and cam in. Looks like the flat tappets are about .160 to .170 shorter to the push rod socket than the rollers are. Larry

[geoffinbc]

Well then you could have just ordered the Magnum rockers from COMP that fit the factory 10mm studs and would not need to use the ARP studs.

[trotterlg]

Yes, I could have done that, but with the flat tappet cam I will need different pushrods also, so for the price of the magnum rockers I can get steel roller tip rockers, pushrods and the adjustable studs and still have a little chambe left over. I think having the valve train adjustable will be a little better than the stock fixed system. Larry

[geoffinbc]

Oh right you have the net lash system. You should have put up a wanted ad I have about 4 spare sets of factory adjustable studs. I also have a set of ARP studs for sale as well.

[trotterlg]

Next time I need some I will know where to come to. Are the factory adjustable studs 3/8 or 10 MM? Larry

[geoffinbc]

10MM. Everything concerning a 60 Degree V6 is metric.

[trotterlg]

Using 10 mm studs really limits the rocker arm selection, there are tons of 3/8 rockers to use from SBC engines. Price for rockers is about half, so I guess the 3/8 10mm studs are a bargin. Larry

[geoffinbc]

Yup you not going to find any aftermarket roller rockers for a 10mm stud. You need to use the conversion stud. If you don't use the Crane Cams kit and decide to use another brand then you can just buy the ARP conversion studs.

The COMP Cams Magnum roller tip rocker does fit the factory 10mm stud.

[1997luminaLS]

Hello I just bought a 1997 Chevy lumina ls with the 3.1v6. What can I do to increase performance?