Originally Posted By Mark Whitener
The Promax is a 51241 BLP metering block with Promax laser engraving on it. My suggestion is order a 51251 metering block from BLP, it has the idle feed lowered. You will need plugs for the mainwells, mixture screws and seals, and gaskets from BLP. To finish you will need a box of 6-32 x 3/16 and a box of 6-32 x 1/8 brass set screws from McMaster-Carr to make your own emulsion bleeds and blanks (3/16), and for idle feed restrictors (1/8). A 61-80 drill index set, a pin vice, and a slow speed drill will get you drilling your own restrictions. All of this and still probably less than $150.


Thanks Mark. Can you explain the reason for lowering the idle feed restriction to those reading. I can't seem to find the old posts that covers the theory of why it is important.

It did make a marked improvement if my idle A/F ration stability on my motor.

(edit) Found it. I think this covers it...Don't neglect to click on the last link on the article. Note how long ago they figured this stuff out. Those guys were serious about making America great back then.

https://www.tapatalk.com/groups/racingfuelsystems/viewtopic.php?f=31&t=18

Last edited by jbc426; 09/04/18 01:22 PM.
1970 Plymouth 'Cuda #'s 440-6(block in storage)currently 493" 6 pack, Shaker, 5 speed Passon, 4.10's
1968 Plymouth Barracuda Convertible 408 Magnum EFI with 4 speed automatic overdrive, 3800 stall lock-up converter and 4.30's (closest thing to an automatic 5 speed going)