Iirc, '92 ish up has the pricier, narrower, single row t-chain req'd due to room that the balancer shaft's gears take up. There was a later change to mount a crank position sensor in the plastic cover. That sensor can just sit there and do nothing in his case.
The replacement [plastic] covers come with a plug for vehicles that don't use the sensor [see below]. http://summitracing.com/parts/RNB-635-502/
Btw, not sure about the earlier balance shafted engines, but the '95 or so up covers have a groove for a silicon seal, rather than a flat gasket like old engines. GM says to replace the cover any time it's removed. The cover comes with seal on it, so gasket kits do not have a seal for them [the seal for the balancer is sold, however???] I would recommend a new GM cover, as the Dorman covers are junk imo.
I might have been a hack job, but I reused my original. I used a bead of rtv on block and cover, quickly put the balancer on to center it, and let it sit overnight. No leaky.
As far as pulleys, afaik his will fit the later balancer. Looks like the old big bolt in center, three smaller bolt setup.