What is the difference in the arms, is it the pivot location or the shape of the end where it hooks into the plunger shaft?

Is it the fact that the SB pump has a longer body?
DD

The SB pump I have has an arm made up of plates riveted together and is narrower than the slant fuel pump arm. The end of the arm hooks into a rectangular hole in the diaphragm rod. The slant arm is too wide to fit the pump body and wouldn't connect to the diaphragm rod even if it wasn't too wide. The outboard (pump) end of the slant arm was actually longer than the SB pump arm. Pivot appears to be in the same place. I didn't want to have to buy a $74 fuel pump, but when the next engine goes in I will.

So do you get away with a 5/16" fuel line on the hot nitrous motors?

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Joshua

No... there is a second fuel pump and line that runs to the N2O regulator mounted on the fire wall.

On your SB HV pump, some of the early Carter SL6 fuel pumps have that "multi- layered" arm... I wonder if I need to dig one out of the box and bring it to Las Vegas??
DD

Doug,

I didn't think one 5/16" line would be safe for a hot motor with nitrous. I have a Holley blue pump and regulator if I need it. Ever try a 3/8" line with the big mechanical pump and nitrous?

Thanks for the offer, but I'll get a big block pump when the time comes. Already have the slant arm out and ready to go. I'm not going to make Vegas this year. Got booked up before I learned the MATS date.

Joshua