Carb Technical ? Jet Sizes

[George Snyder]

I am ready to make a switch from a 650 Holley to a 650 Speed Demon. I have a 302 Crate Engine. I have visited the Demon site and did some research. My question is this. Why would a Ford 302 need larger jetting than a Chevy 350-ZZ4. The other settings in both carbs are close to being the same.
I am using 64 & 67 in my Holley now. They could easily go up a few sizes without fear of fouling the plugs.

MODEL # 650 Vortec 650 ZZ4 650 Ford 320
PART # 1282818C330 1282010CZZ4 1282010F320
VENTURI SIZE: 1.280 1.280 1.280
IDLE AIR BLEEDS PRI: .059 .059 .059
IDLE AIR BLEEDS SEC: .063 .063 .063
H.S. AIR BLEEDS: .041 .041 .041
BOOSTER TYPE: DOWN LEG DOWNLEG DOWNLEG
BOOSTER LEG: .140 1.40 1.40
SQUIRTER SIZE: 31 STD. 31 STD. 31 STD.
BUTTERFLY SIZE: 1-11/16 1-11/16 1-11/16
AIR HOLE SIZE: NONE NONE NONE
PUMP CAM # # 330 # 330 # 330
PUMP CAM COLOR: PINK PINK PINK
VACUUM SEC. SPRING: N/A N/A N/A
METERING BLOCK # P. A-12400 A-12400 A-12400
METERING BLOCK # S. A-12401 A-12401 A-12401
SIPHON BREAK: .028 .028 .028
E-HOLE POS. #1 .031 .031 .031
E-HOLE POS. #2 N/A N/A N/A
E-HOLE POS. #3 .031 .031 .031
E-HOLE POS. #4 N/A N/A N/A
E-HOLE POS. #5 .031 .031 .033
P.V.C.R. SIZE: .059 .059 .059
TRANSFER SLOT RES: OPEN OPEN .OPEN
IDLE FEED RESTRICTOR .033 .033 .035
MAIN JETS PRI: # 70 # 76 # 85
MAIN JETS SEC: # 78 # 83 # 93
POWER VALVE PRI: 6.5 STD. 6.5 STD. 6.5 STD.
POWER VALVE SEC: N/A N/A N/A
LINKAGE TYPE: PROG. PROG. PROG.
N&S SIZE/TYPE: .110-VITON .110-VITON .110-VITON
ACC. PUMP DIA. SIZE 30CC 30CC 30CC

Bud

Nothing to add! The post was close to falling off the page with no answers.