Push it past 35 amd see if it smooths back out.
Yeah, time delay response... As mentioned, there is a right rear axle rhythmic sound/bump/shudder at 25-35MPH. As Action suggested, it seems to smooth out and disappear at 40MPH. Drive-train seems ready/willing/able to go past 45MPH [but I restrained myself due to loose tie rod ends and ball joints and leaking power steering.]
Pulled a "new to me" loaded M1102 without major issues, but sloppy tie rod ends mean I gotta clean up the suspension this week before taking any chances above 45MPH.
I have centromatics to install, along with new shock absorbers and new uncracked rubber. Tie rod ends and ball joints all gotta go. Axles look ok [meaning rubber boots intact], but might swap them out to be sure in near future (and keep these with unknown CV joints as spares for emergencies on the road). Gonna get new power steering box rather than rebuild current box. This forum mentions this is just a regular off the shelf box, so why not just get a new one and be done with it for the next 20 years? Gotta look up the power steering part number, I guess.
I also don't like the alignment and wear patterns of the rear tires. Camber is off/positive (look like lower edge is in further than upper edge), so shims will need adjustment (or I can add 300-400lb of sandbags to the back).
As mentioned in another thread, I purchased new bolts that prevent loss of wheels at speed.