Would have to switch intake or weld water plenum under intake. My vac at idle is 22.
Today I went back to Clifford starting jets MainJet 48 squirter 31 power valve 8.5
and had lean stumble off beginning of gas pedal press. When I put in 9.5 it was better when I put in 10.5 it worked great but still had a slight one so I installed 49 main jet it was better but ended up leaving a 50 main jet in and I liked the 28 squirter and took out pink cam and left orange in. I am really happy with my seat of the paints one circuit at a time till I got my best results so far.
700 idle manual Trans 50 main jet 28 squirter 10.5 power valve and orange pump cam in #1 hole
Rebuilt chevy 250. Rebuilt head with Clifford's valves and runners cleaned up. Clifford long headers. Clifford older intake no water. Holley 390. X pipe dual 2.25 pipes with 3 chamber mufflers.