ive got a 2 barrell carb on my motor now that i bought off of kybuggy1 on here would that 2 barrell be big enough for a 1915?

If you can scrounge you can do it. What carb do you have? I have a 1835 with a single 2 barrel Zenith that lasted 19 years. It has a Webber VZ 15 style cam ground on 110 lbe centers, Webber HD singles springs and Webber lifters in it. It has a used line bored case. Used stock std. crank and new stock Rimco rods with new bolts and nuts from Rimco. It had a used lightened flywheel with used Sach disc and used Gernman pressure plate along with a used 1.5" Tri Mil exhaust. This engine was a test to see how cheap I could build one and still be reliable. I had a set of used 041 heads and HD rocker shafts. Being econo I used the stock valve spring retainers, push rods and rockers. Eventually I pulled a set of locks through the stock retainer and bent a valve. Lapping in a new valve and set of HD retainers solved that. I did splurge on a Melling oil pump and Gene Berg pressure relief cover dual oil filters and a Mesa style oil cooler and electric fan. If you blueprint a Schadeck 26 mm oil pump it will be fine and over $120 cheaper. The only thing I would do different is use a VZ 14 cam next time. The 15 worked great with a 3 rib bus Transaxle and 30 " tires. In year 19 the switch to 33" tires overworked the engine and the rings gave up.