information needed to use perkins engine to drive sawbench

i have a sawbench which was bought by my late father 60 years ago and I want to mount it on a frame with axle and I know of a perkins 4107 which was used to drive a drier of some sort. I would like to know what is best RPM for sawblade there is flat belt pulley on saw bench and engine has V pulley I am thinking there will need some sort of pulley between engine and saw bench also what is minimum distance for best driving between flat pulleys regards Ivor

Depends on the blade diameter which is calculated to give the correct peripheral speed.

https://vermontamerican.com/circular-saw-blade-speed-chart/

Back to the saw bench, It does depend on what you are cutting and number of teeth and size of blade, you need to think of teeth per second rather than rpm. Big teeth for ripping softwood etc. will have different needs to small teeth for fine cuts...