Hi all, did 70 Riv GS come with the Stage 1 heads? How about a posi? What sive is the ring gear? Thanks.
I'm not sure about the heads but all pre-1973 Riviera GS models came with a 3.42 posi as standard. The gears aren't the same as on Skylarks. I think they are 9 3/8.
Yes Phil, you are correct on all counts. GS Rivs have 3.42 posi rears and the ring is 9 and 3/8". However... There have been SEVERAL CONFIRMED cases where a 1970 GS Riv came through the factory with Stage1 heads. Not all of them did, but there are documented cases where some did. We in the Riv community have not been able to find out why this is. And the ONLY way to know if yours has Stage1 heads is to pull a head off and look at the valves. Easy weekend job, BTW, if you really are wanting to know...
