I have a Holley 1850 from probably the 1960s sitting in my garage. It's got a hot air choke, and all butterflies are free, but it's cruddy. I'm running an old Edelbrock 1406 on my Mustang's 289 right now, and it's dialed in close on my wideband, but the idle/transition circuit is a little lean (at light cruise, it surges a bit and runs around 15:1 or so). Once I'm off the transition circuit, it richens out a bit and doesn't surge. At curb idle, it's at 13.4:1. Anyway, I'm thinking about trying this old 4160 rather than do any potentially harmful opening of idle restriction passages in the E-brock. I know I'll have to put in a power valve check valve, but what rebuild kit would you guys recommend (part number, if possible)? Most of my experience is with Carters, Fords, single barrel Rochesters, etc., but I know my way around a Holley reasonably well. Any guidance or advice would be appreciated. Oh yeah, the 289 has Tri-Y headers, a 204/214 @.050 cam, Weiand intake...basically a mild, mild build. I'm thinking of using the Holley because I have it.