the regulator is inside the alternator and yes you can take the alternator apart and just replace the regulator.
Everything should bolt right up.
Almost all GM alternators (circa 1970 and newer) have a fully integrated Delcotron alternator. The regulator is inside the alternator.
you should be able to unbolt the motor from the firewall on the passenger side of the car
first what i do is take pictures of the wires and the bracket then u take off the wires from the back of the alternator make sure u know where they go then take off the 2 bolts holding on the alternator.
One place to get parts for a 1970 Pontiac Grand Prix is at the website Stock Interiors.
About ten minutes if you've done it before. Not much to it. Disconnect the battery, remove the mounting bolts and wires. Installation is the reverse, except for tensioning the belt.
There were 2,170 convertible GTOs in 1970.
A 1970 Pontiac Service Manual will have this info in it. You can find them on Ebay or one of the literature places on the web.
Weight on my Pontiac LeMans Sport registration is 3800
maby you should Expierement on it or go ask google ok sorry.
passenger side on engine.
There are many places one can go to to purchase a Pontiac 1970 GTO. The best place would be your local Pontiac dealership to help locate you one. You can also try AutoTrader.