When trying to get her to idle don’t overlook the timing advance I had the same problem with the 261 in my 56 even replaced the carb with a new one and no luck.

All it took was a small turn of the distributor and she ran great.

Like Tri5 said we like pictures sounds like a great truck so the other V8 truck is that a Buick nail head, or a 265 SB Chevy? Is it stock???