anyne kinow difference? from what I can gather from thee next, m970 is 3 chainring but with alloy cage; wheraes 980 is the same but stell cage? anyone confirm that?

m970 = 130 g, m980 = 142 g (due to alloy cage no doubt - somehow an alloy cage to rub against a chain does not seem like a good long term proposition).

hmmm ... seems both have alloy cages 970 is 9sp and 980 is 10 spd as far as i can tell

I don't think either have an aluminum cage. Probably not since the 950- series.
The m980 is 10speed. The m970 is 9speed. Because the m980 is 10speed, it is designed for a 42t outer ring, the 9speed is based around a 44t ring.

brilliant info ..... I guess I should have twigged after trying to use a 10 spd SLX front mech.

so it is m970 I need.

re: spec.
Shimano XTR Front Mech E-Type 9sp M970 Specifications :
Series: XTR
Model No. FD-M970-E
Rear Speeds: 9
Front SIS :Yes
Chain Ring : Triple/Double
Top Swing Link : Yes
E-type BB Mount : Aluminum
........
BB Plate :Aluminum
Outer Link Material/Finish : Steel/Painted
Inner Link Material/Finish : Aluminum/Painted
Chain Guide Material/Finish : Aluminum/ Nickel Plated