Carb changes any guesses

I am going out to Rock Falls this Wednesday the weather looks good so far. I went a 10.44 followed by a 10.42 the last time. with my 750 Edelbrock cabed tunnel ram intake. (Nostalgia look) this time I will have a pair of 750 single fuel inlet Holley's with vacumn secondarys with the lightest springs that I have. I do have a pair of small screws in the slotted carb lever if I feel that they are not coming on fast enough just slide the screws a bit and tighten down (crude I know but it has worked in smaller and  (MUCH LESS HP ENGINES) i have used in the past. Any guesses? Oh by the way the carbs are facing the proper way not sideways

57ford custom wrote:I am going out to Rock Falls this Wednesday the weather looks good so far. I went a 10.44 followed by a 10.42 the last time. with my 750 Edelbrock cabed tunnel ram intake. (Nostalgia look) this time I will have a pair of 750 single fuel inlet Holley's with vacumn secondarys with the lightest springs that I have. I do have a pair of small screws in the slotted carb lever if I feel that they are not coming on fast enough just slide the screws a bit and tighten down (crude I know but it has worked in smaller and  (MUCH LESS HP ENGINES) i have used in the past. Any guesses? Oh by the way the carbs are facing the proper way not sideways

Install the large 50 cc accelerator pumps on the carbs and start with about .045" pump shooters

Parts are ordered thank you for the advise on that. Might even get them installed before Wednesday.

Installed the .045 shooters today and also the large pump. Tried to change the pump shooters without taking the carbs off and damn near dropped a washer down the carb throat so took the carbs off and did it the right way on the bench.

Took it out late this afternoon with the Holleys and the weather was bit warmer than when I was out with the Edelbrocks. Made 4 passes the best was 10.556 at 128.62 and that was with my opening the secondaries right on launch. (with my small bolt in the linkage) Shifting at 6500 and crossing the lights somewhere over that as my memory tach says 7500. I think my converter is maybe slipping a little on top end. It has been in the car for many years. I foot brake it to about 2000 rpm. I have kind of a little backfire or miss when coming back on the return road so have to see what that might be as it sounds funny kind of a pop pop pop as I am on the return road. Its now my opinion that a 750 Edelbrock is fairly close to a single fuel inlet 750 Holley regardless of what amrchair racers might tell you. In fact the throttle responce (seat of the pants feel) actually seems a bit quicker with the Edelbrocks. The clocks don't lie. Oh I forgot to mention I made one pass after taking my (cheap charlie) ram air off and it fell on its face after 100 mph and it looks good to me anyway. . 60 foot's  were terrible as the best was 1.63 as a  good one with this car is in the high 1.40's

Mechanically opening the secondaries (with a nut and bolt) will cause the 60 foots to drop - without a pump shot it normally will encounter a lean condition, the severity of which would depend on the amount of opening. My own thoughts are that the 45 squirter helps, but cannot remedy that issue.
Just curious, what is the list number on the carbs you're using? I didn't know they made a single inlet 750 vacuum carb. Or did somebody convert these for you?

I don't know the list number but I have never seen this carb before so it must be a new addition. Just look in the summit catalog and you will see it listed the price is pretty reasonable at around 365.00. The (seat of the pants) feel was good but another friend that was along said his wasn't launching like it should and there were quite a few street cars there they were MAYBE making it a bit slippery. My wife said it looked to be moving sideways a bit and did notice that also. She was suppose to film the last run but screwed up phone camera (easy to do) so I told her we would try it again next time we are out. Also blew a little water out so am going to buy a new radiator cap and remove the thermostat and put a plate in with a 1/2 inch or so hole drilled in it. Any suggestions in the size of the hole as I can always drill it smaller to begin with and make
it bigger.

57ford custom wrote:I don't know the list number but I have never seen this carb before so it must be a new addition. Just look in the summit catalog and you will see it listed the price is pretty reasonable at around 365.00. The (seat of the pants) feel was good but another friend that was along said his wasn't launching like it should and there were quite a few street cars there they were MAYBE making it a bit slippery. My wife said it looked to be moving sideways a bit and did notice that also. She was suppose to film the last run but screwed up phone camera (easy to do) so I told her we would try it again next time we are out. Also blew a little water out so am going to buy a new radiator cap and remove the thermostat and put a plate in with a 1/2 inch or so hole drilled in it. Any suggestions in the size of the hole as I can always drill it smaller to begin with and make
it bigger.

What fuel?

mixture of 110 and c14 but I have run it mostly 110 and sometimes adding some 93

1/2 sounds like a good starting point to me.

Start at 1/2" and go up from there if you need to. Are you running a belt driven water pump, or electric?

Mezeire electric

What size stat?

No stat now as I changed it yesterday. Haven't fired it or warmed it up yet as it is kinda noisy.