The v6 trucks are a knda PITA you will have to remove the lower control arms to get rid of the 4.3 mounts and depending on what mounts u use (I used Trans Dapt from summit)that use the SBC clam shell mounts you will have to slot the holes in the k member to raise them up higher to line up correctly. A lot easier to get your mounts set up if the front clip is off the truck.You will also need to grind the bead roll off the clam shells so they bolt up flat to the engine plates. If you take your time you can make them fit like a glove em what th
As far as wiring I went with a reworked harness off ebay but ended up selling it (it was pretty sloppy)Had Nelson do a custom Harness and never looked back.The are show quality and the will make them how ever you want them I had them make the wires for the coil packs longer to move them off the valve covers and over on the inner fender . If you Have any questions PM me Be glad to help