Those manifolds are pretty decent compared to most other Ford manifolds , those guys that run in the F.A.S.T class port the dickens out of those manifolds , it'll be a nice sleeper

Nice package! Blair's building mine similar to yours, full CNC BBM B's with T&D's, 482, TFS 2x4, small solid roller going in a 65 Fastback that's back halved with modified 68 shock towers, hopefully we will have or be close to your power numbers too

you need to get the idle solenoid and then figure out where to put it on the passenger side, front carb , rear carb and/or the driver side linkage once you actually have it in your hand, on my 2x4 it looks like it may fit front carb passenger side but will need a longer carb stud to accommodate the thickness of the idle solenoid bracket

Roller rocker arms are where you'll have interference trouble

I'm having a hard believing .016 thickness too

we had a pile of these plastic stud gasket aligner deal thingy from other engines that you just screw right into the rail and it holds up my two gaskets and my windage tray until I can install the pan from on the ground and start a few bolts , then just unscrew the aligner stud
the four plastic alignment tool is pictured in the Summit add and comes with the SBC gasket set among others
https://www.summitracing.com/parts/fel-os34500r?utm_source=bing&utm_medium=cpc&utm_term=%2bfelpro+%2bOS34500R&utm_content=Fel-Pro&utm_campaign=Part+Number+Ad+Groups

If you do the appropriate bowl work with the larger valves it should pickup flow, I have no before or after but most of us clean up the ports and open up the throats accordingly when you go bigger valves, I did that on some 2.10/1.65 valves for C1AE's in my 63 Fairlane 390 with mild cam 237/247at .050 with 559/579 lift Lunati solid lifter and 3x2's (not the best intake) run a nice 12.50 at 108 good air and 12.78's hot and humid at Kilkare now called Dorona Xenia in Ohio and real driveable on the street

Cheap wires or you don't have them plugged all the way on to the spark plug, spark finds the easiest way to go