Pulley spacing?

Hi guys, I?m in the process of installing a new engine and the mounting bolts don?t line up. I?m going to have to drill new holes and I can?t find the measurements for how far to space the center of my crank shaft from the center of the T-20 driven shaft. Am I missing a tech section somewhere where there are oem measurements and data that I can find or does anyone have the correct spacing measurements?
Should I line up the dive pulley with a certain spot on the driven pulley or just ?get the belt straight??

i'm not exactly sure ..but if you have the belt , set the motor in place with the belt on both pulleys so it's straight then pull the motor forward till belt is tight . somehow clamp the motor so it won't move . when you push the top of the belt down there should be about a inch or so deflection . it's best if your new mount holes can be slotted so you have a bit of adjustement forward or back on the motor so as to get the belt just right . hope this helps , someone may chime in and let you know if this is the way or other suggestions . johnboy va

Thank you sir! My belt was way too loose to start then. It was floppy in there before.

Rowdy, look on this chart. Match up your belt and pulleys and see what the suggested center distance should be.

https://www.bmikarts.com/Comet-Belt-...16-Width-Belts

Fantastic, thank you sir!!!