The 50cc pump worked for my application. I had a heavy car with slicks and it would bog all the time @ the track. Its a simple change that worked. For the record the car had a mild 440, 4:10s a 4 speed, open headers and a 10" slick.
Pink pump cam pos #1 (30CC) .035 squirter- purple springs
car is responding 60 ' times 1.80-1.84
next issue car is not pulling thru eyes- "I'm shooting ducks"...has to be timing
distributor is stock out of the box Mopar electronic- been on the car since '96
current timing 10.5 initial -36 total
should I be experimenting with different spring weights?
Any help appreciated
Hope to get to the track in early October for the my season finale
A stock fuel pump at normal volume and pressure should be more than enough to supply fuel to that engine. The needle and seat hole in the carbs is barely an eighth of an inch. Another possibility - and I've had this happen - is the fuel pump push rod may be worn to the point it's too short thereby not giving the fuel pump enough stroke. Remove the line, shove the end in a coke bottle and do a volume check. Don't over look the plugs either. I've had similar issues that were fixed with a fresh set of plugs.
You must have some non standard heads because that does not sound like a big block plug number. I guess if you are not fouling they should be OK. If you have an MSD then you can gap at .045", but one thing at a time.
The 12Y is OK for the street, but is too hot for the track. Change to a cooler plug. I always had better luck with the AC short reach plugs, don't remember the #, maybe 44 or45S. Or try the Autolite racing plugs with a short reach, should clear up the high end miss. IF changing to the cooler plugs does not work, then more fuel is needed as you are too lean. Maybe open up the metering block 1 # at a time. But if you drill yours out, there is no going back to the leaner setting if you get it too rich.
The stock fuel pump mayor may not be adequate. I raced a 69 six pack car back in the day and had a surge in 4th gear. Could not get rid of it until I put a HEMI mechanical pump on it. No more surge problems.