I'd agree with this as well. Since you already have the L31, research your cam options, add a set of headers get an 0411 ecm and tune it.
Just a little update. Got all the parts on order. Reusing most of my top end from the 350, including the intake manifolds. I already bought a new upper 2 months ago. Might as well lol.
I got the new MFI conversion. I bought the kit from oreillys, they carry them at almost every store apparently. I know spider injectors are expensive. And this system cost just as much. It's part number FJ504 if interested. Puts the injectors at the end of the hose into the runner unlike the original system at the front of the hose. I'm sure most of you are familiar with this system.
Basically just gonna be a vortec 400. Might touch up on the heads, port them some and get some bigger valves. I'd rather invest my money into a 14 bolt and 6 speed auto swap. I have all the interior bits for a 2016 chevy truck too. But were getting off track.
I'll update this thread in a month or so with some numbers and parts. I'll go back and look at what I ordered and show what parts I ordered.