L have the firing order for my 350 chevy

Position engine at TDC. Make note of direction rotor turns while doing so( Clockwise or counter). Make note of exactly where rotor is pointing. install cap onto distributor and insert number one plug wire into cap hole that matches location of rotor tip. Then using direction of rotation and firing order install remaining plug wires. Best way to determine TDC is to remove #1 plug and bump motor around with finger covering sparkplug hole. When you feel air escape hole you know u are aproaching TDC. just use wrench on crank to line up timing marks. Do not engauge starer with wrench on crank just turn clockwise by hand. Engine is now dead timed and will only require minor adjustment by timing light to complete job.