[78-5.3]

so you have a 91 truck blazer burb?? and you want the tacho from a 76 to fit into the cluster and for the wiring to work??? i dont think it will im going a similar route 91 cluster with camaro tacho into my 78 truck the plug in the back is going to be the problem i think i have to cut into my cluster !!! i never went for a truck tacho coz of the 5000 rpm limit!!!