47-55.1 Eliminate draft tube options

[leegreen]

you have a unique setup, what is compression ratio and boost expected?

.035 would be typical for a 235/261
Electronic ignition can spark a wider gap, bigger spark for cleaner burn. 045 for HEI SBC

high compression & boost may need smaller gap for if the spark can't jump a big gap in a high density charge, but I doubt your going to be driving this beast that hard in the near future. I wonder if 020 is more to make it easier for magneto to spark?

030 to 035 should be pretty safe
25 foot pounds sounds about right, I just snug em up with a 3/8 ratchet on iron heads