What engine management are you using? We have a buggy that has a '91 5.8 with a c6 behind it. It has issues with stalling. we stripped the stock harness down, but curious if there is a better option?
I think there is. As they say, your mileage may vary.
My buggy ran a Microsquirt on the 5.0, I put a crank position sensor on to support that, and ran batch-fire injection, wasted spark distributorless ignition, and it ran well. This one I'm stepping up to Megasquirt to get sequential injection, per-cylinder ignition, per-cylinder knock management, per-side O2, and a more-boost-ready controller. Obviously, I'm a fan of the Mega/Micro squirt line. It is a nearly start-from-scratch engine management build though. If you don't want/need knock control (Microsquirt "can" do it, but IMO the method is a bit kludgey and not great on Ford engines), are good with batch injection and waste-spark ignition, the Microquirt is a great way to go. If you want more out of it, Megasquirt is right there, but it's a big $$ step up from Micro.
I had a Quarterhorse on the Ford EFI once upon a time, it was great when it was good, had something else before that, had off-n-on problems, went through a stock harness, bought the Ford Motorsports standalone harness, went through that, threw sensor after sensor at it, finally stripped it off and put a GM TBI on instead, that was great until the computer failed, then it turned into a mess. That's when I went Microsquirt. New DIY harness, Ford IAC, Ford TPS, GM IAT, GM Baro, GM MAP, Ford (Bosch) injectors, wideband O2, VW Beetle logic ignition coils, Ford crank position sensor off a '99ish Explorer, crank wheel off the Explorer, short/reverse timing cover and water pump from the Explorer, etc. The '96 Bronco has a long reverse rotation water pump and the same timing cover as the Explorer if you want the equivalent 351 parts. It also has a four tooth crank wheel (not useful) on the same size/location register that you can push the Explorer 36-1 crank wheel onto and have it line up nicely with the Bronco/Explorer (they're the same) crank position sensor. I made a half-n-half cam position sensor out of the Bronco 351 distributor and an Explorer cam sensor assembly.