If you got the tools, the mechanical ability and the time I say go for it. I did mine ''in cab'' and all in all it was not to bad. It took about 5 days of working at my own pace. The part that I thought was going to be the hard part was taking the AC blower box out and all that crap but that was a breeze, 6 nuts behind the glove box and a few other things in front of it and out it came. The heads are not light so be ready. I pulled my wire harness out completly and that looks bad but all the connectors can only connect back to where they came from. Other than that just make sure when you go back together that you clean up everything real good and dont take short cuts.
Oh one more thing, take pic's as you come apart with it step by step. It will really help when you go back together as far as where certan bolts go ex. like intake, valve covers ect.....
Go for it!