Whats needed to fit roller cam into my 1971 340?

Hughes and others sell a retro roller hydraulic lifter that has the oil band located lower on the body to eliminate oil band exposure at the lifter bore top. Some people have had problems with the retro rollers in that they won't pump up due to poor/incomplete machining. I used the Hughes version in my brand new used rebuilt 360/408 LA non roller block with no machining or problems. Just get the push rod length correct and you shouldn't have a noisy valve train or problem. I would go with roller rockers too, I used the Hughes version. I didn't know what people really meant by torque monster till I put the 408 in and stepped on the loud pedal. Now I gotta find traction.
Edit: That's a pretty hefty cam, more duration than my Hughes SER3438ALN-10 but less lift. Idle vacuum will be low. Don't know about the 340 but with the comp xe268h I had issues with in gear idle and a tight converter due to low vacuum in a small bore 318. Took some time but I got it acceptable with an adjustable vacuum can on manifold vacuum and some t-port sync and idle circuit mods in my Holley 4150 650 cfm carb.