new to site question about pulleys

I'm thinking that the early model LA engines 273, 318, 340 had a smaller crank pully back then. I ran into the same problem about 10 yrs ago when I was racing a dirt track car. Turning 7500 rpm I needed to slow the water down. I'm not really shure about a 4 groove pully from that eara the one used was a one groove. I may have one that might work for you in the barn. I will check it out tomorrow.