Just fitted a new sram chain to the bike, and replaced the block with a shimano one, the chain when being wound backwards seems to jump up and down on the rear cassete, and applying pressure forward pedaling just makes the chain jump also .

Fitted a new sram cassete and all working hunky dory.

Oh and how do you split a speed link, seem to have no problem going up steep hills 2 in a few months, but cant get the little blighter apart, today.

Any other ideas.

no sram has a different ratio to shimano…..

chain and cassteete will work. the ratio is in the shifters/rear mechs

So will a Sram cassette work with M970 shifter & M970 mech?

yeah

Yes chain and cass will work fine mate.