Hey guys, lately I've been having some issues with my 02 blazer 4.3L when going up hills, mainly on highway I'm losing power to the wheels but my rpms will spike a bit no higher than 3k rpm and drop back down to normal within a second or two.

I notice sometimes it's a little sluggish pulling away but not that often. I've been told it sounds like my clutch by one person and was told vacuum leak by others so I'm looking for a little more experienced input.

This is my first standard vehicle(driven others off and on for roughly 6 years) so I'm still learning the signs of clutch issues.