HELLO I HAVE A QUESTION CONCERNING MY NEWLY RESTORED 1995 TIGERSHARK MONTE CARLO +, ITS A GREAT RIDE! BUT I NEEDED A LITTLE MORE PEP, SO I ADDED A DAYTONA TWIN CARB TO MY 640 ENGINE, YES THEY CAME OFF THE SAME SIZE & YEAR ENIGNE. I FOUND IT STRANGE WHILE I WAS PUTTING IT TOGETHER, I HAD VERY LITTLE VACCUM ON THE MAG SIDE CARB, BUT PLENTY ON THE PTO CARB. I COULD COVER THE FRONT CARB & NOT CHOKE OUT THE ENGINE, BACK CARB CHOKED QUICKLY. ENGINE WILL RUN ROUGHLY IF #1 OR #2 PLUG WIRES ARE REMOVED AS IN SAFE MODE. ARE THESE ENGINES SUPPOSED THE RUN WITHOUT VACCUM TO THE FRONT CARB? AND IF NOT, WHAT TO CHECK FOR OR HOW WOULD I GO ABOUT REPAIRING THIS?