01 rolla/prizm renewed, but now has the shakes :(

Whoa, been a while since I've posted here, but still holding on to my 01 rolla.

01 Prizm still running strong at 235K miles with a reman Jasper engine installed at 151K. Went through a couple cat converters and an engine mount, until recently when the rack siezed up. So it now has a new rack and pinion, all new suspension/tie-rods/sway links/new tires/tune up with new plugs. Both of the lower engine mounts got replaced as well, yet inexplicably, the engine shakes when in drive but stopped (red light) and when speeding up to 50-55mph, then stablizes smooth. I suspect the engine mounts were not installed correctly but wanted to run it by folks here. Thoughts on what could be causing the shaking?

have you checked tires balance,cv axles,and bearings ?

All new axles/bearings and tires too.

cleaned the throttle body and maf sensor/iac possibly and maybe fresh o2 sensors. kinda hard to help on that end

It was the third engine mount, got it replaced and added an extra bushing underneath one of the bolts since the exhaust was vibrating a lot. Thanks for chiming in guys.