what the diffence in ho motor and standard motor in astro van cpu, or cam, etc ?

High Output uses CMPFI central muti-port fuel injection-a 61 psi fuel pressure requirement- recognizable by the intake manifold and air cleaner set-up- the standard uses a throttle body- lower fuel pressure and air cleaner right on top of engine --- after '93 all M-vans were high output......a much better set-up.....

ty 4 your reply i am familar with the cmpfi i have a 94 s 10 blazer im asking about a 91 non vortec balance motor