Metering block questions and differences?

[BHollinshead]

I got a good look at some old 750 Holley tunnel ram carbs today, these are list number 6109. Some of the metering blocks look just too corroded to use. I've heard these were really good carbs and don't have the rich idle circuit the 660's are known for. I measured all the metering block drillings and the high and low speed air bleeds with thoughts I might build a new pair of 750's and this calibration might be a good starting point. I attached all the measurements I recorded. I also attached a photo of the blocks and it shows the difference in drill angle for the booster feed circuit-is this normal? And if I order aftermarket blocks do they come this way? notice how small the idle feed restrictors are. Does anyone know how these measurements compare to a basic 4779 750 double pumper? or a 660 center squirter? Where can I find the specs on the 4779 blocks? I also think it's odd the power valve is 8.5 and wonder if this is just to enrichen things faster. The channel from the mainwell to the booster is .140" which seems large. I measured a block from a 500 two barrel and that one is only .130" Interesting stuff

[Ndean]

Hi . The primary block you have has the same specs as a 3310 block except for the IFR at .037 , the Horizontal angle channels in the secondary block are to help prevent spill over during braking , I don’t think that new aftermarket blocks can be bought with the horizontal channels but I could be wrong .

[BHollinshead]

Awesome thanks for the help, 3310 blocks are easy to find.