I called the Summit tech line and told them I was swapping out a 350 from 1975 to the Chevrolet Performance 12681432 L31 and here is what I was told.
Intake Manifold- Gave me the edelbrock at $232
https://www.summitracing.com/parts/edl-7116
and Summit model. He mentioned I would need the Square Bore Manifold to Spread Bore Carb plate also and gave me this item number..$35
https://www.summitracing.com/parts/trd-2109/overview/
Electric Fuel Pump- He said there were a huge list of them to choose from, I mentioned the one Gary mentioned and he said that would have been a first choice for him as well -$45
https://www.summitracing.com/parts/hly-12-427/overview/
He also mentioned mounting it as close to the tank which for me is in the cab. Then he talked about there could be alot of additional things like the filter and probably a bunch of other parts that would likely be involved...and that the shop I have do it would be the ones to tell me. But with this being done in my garage I hope there are some quality and accurate how to's out there and a list of what to gets or I might mess things up.
Flexplate- he said it wasnt needed. I asked are you sure? He said yes the L31 isnt the LS engines that would have been from the year 2000 onward.
Melonized gear- he said it wasnt needed. I tried measuring the dist shaft that I took off the engine and Im not sure Im measuring the right spot. He said as long as its .5 inch it will work, but .8730 is what the caliper reads if I measure the outer diameter of the end of the shaft. The inner diameter portion is .49