Not sure what thread the stud hole is in the head, but there should be no harm in running that diameter if if screws in or the make on the necks up to that size. If it would require to redrill then I can't say. The 1.7 rocker also shouldn't matter providing its a sbc 1.7. Bbc 1.7 ratio with 7/16 looks the same but they are indeed different. The 1.7 will just make the valve opening, max lift, and duration @50 bigger and faster, but your seat to seat duration won't change, nor will the intake centerline or the lobe seperation....but every other cam event timing spec will. Let's say you have cam that cut to give you .525 with the stk 1.55 rocker......with 1.7 rockers that valve would now open .575. No big deal as long as the springs have that in them and there is enough clearance between the piston and valve.
Thanks Ben all that info is very helpful. I asked the guy if they were sbc or BBC rockers and he said they were BBC 1.7 rockers.
Yep they have the same size stud, but the distance from the studcenterline to pushrod cup and roller center, I'm pretty sure are different distances on the big and small chevy
Correct on the above info. You'll have to stick with SBC rockers. The ratio difference is changed by shortening/lengthening the pushrod to fulcrum (stud) distance. The fulcrum to valve distance is fixed and has no play on rocker ratio. The BBC fulcrum to valve distance is longer than SBC, so no-go. Another thing to keep in mind is that the higher the ratio, the more stress on everything from the pushrod tip to the camshaft. There's a lot to be said for staying away from high ratio rockers and building the desired valve timing specs into the camshaft instead. Devon
Good info there Devon thank you. I'm going to continue looking for the proper 1.6 rockers. I'm not opposed to changing the studs from 3/8 to 7/16. No extra drilling is necessary, edelbrock made the stud holes and stud shanks that go into the block the same diameter and thread size so it's an easy swap.
I will say used 7/16 stud sbc rockers almost always would had been used on a higher rpm motor. Meaning they most likely are well used. 400 bucks gets your comp pro.mag with a great warranty
I asked that.....I dobt know if they are already 7/16-14 thread in the head or if they need opened up to it
The eddy heads are drilled/threaded to one size, (7/16 I'm pretty sure) the shank on the studs screw in the same no matter what ones you get. It's the top of the studs is what changes for the 3/8 vs 7/16 rockers.
