What are the differences between YT 6658 and YT 6656? Will the ones for the S1VN bolt up to a VR buick, or am I just making more work for myself?
The YT 6656 are a 3/8 mounting bolt and the YT 6658 are 5/16 mounting bolts, both are the same rocker arm just different mounting hardware.
Normaly the Early Vn heads use the 3/8 mounting bolts, but i have had a few vp/vr that had the larger bolt holes insted of the 5/16. it best just to pull a cover off and check what they are before buying any rockers
Cheers
Micky.D
YT