Are you sure you have adjustable valve train?
4.3's had rollers from 1988-1995. the V8's didnt. starting with the vortec heads, GM went with non-adjustable valve train.
Odd thing is if I wanted a reman 4.3 from 87-92 which is my casting number series, Michigan Motors sells them with only the flat tappet!
the 4.3 in my 95 has a roller cam, but does NOT have adjustable rockers.... run them down and forget them.... and despite the valve covers, this one is pre-Vortec.
I'm not sure what besides the lifters would make them adjustable. The lifters are hydraulic and compress while doing the final 1 turn.
old school Chevy engines had a stud, rounded fulcrum washer and locknut. You set the preload on the lifter by cranking down on the locknut, but it never bottomed out, it balanced between the valve spring tension and the lifter preload. if a lifter was a bit noisy, you had a measure of adjustment with that style of setup. Newer engines have a bolt and a positive stop you run down to, there is no locking and no adjustment available on them. set em and forget em.... easier for assembly line monkeys to do quickly......no way to compensate for a slightly out of spec part though......
