Most folks go electric, even GM depending on gen.
Here is my thing; had a v8 60 and a v8 80. Have had v8 chevy work trucks. All these have been mechanical fan. Have also done a v8 swap in an 80 with electric fans. Mechanical fan will pull way more cfms, no power draw. In all my years with Chevy v8's, none have ever had over heating issues except the v8 60 which had a crap fan shroud. So custom fan shroud and the right fan and problems gone. The LS swapped 80 with electric fans, no probs keeping it cool but did run a bit warm in summer months, 195-205*. Intake temps on 100* days got extreme causing issues, IE 200* or more. Logging hundreds of thousands of miles on GM v8's in stock configs never have had cooling issues.
Any ways, myself, I like mechanical fan set ups in v8 or diesel swaps. Just takes the right shroud in my opinion. I would rather have a hp draw vs a power draw and mechanical with a proper fan clutch doesn't care about things that make electricals upset.
What has made this swap challenging is the LS3 intake manifold vs vortec with the mechanical fan set up. It was never offered from GM in this config, vortec is much taller offering more clearance fan to shroud to intake. Certainly would be better with as vortec intake manifold for clearance but regardless, we made it fit. That and mating the LS3 to the NV4500, another never offered from GM. Sum it up; doing it this way with the crate ERod, mechanical fan, NV4500 has certainly complicated the swap. However, it gets you an Erod in a more "truck like" config, I am looking forward to the test drives!
Cheers
