You have stock heads and stock intake? Didn't pick up any changes in the sig. If so, they are the biggest bottlenecks on the engine. The stall converter will help some, but the B is definitely not designed to go with stock heads and intake. The lower intake is extremely restrictive, and the stock heads are right behind it. I doubt the cam will make much difference except for the fact that it will kill the bottom end. PM "Minion" - he'll tell you the best mod he ever made was taking the B cam out of his otherwise stock engine and putting the stock HO cam back in. Having your stock heads ported and getting a ported lower intake from tmoss will make a much bigger impact than putting the B in the motor the way it is.
However - upper intake and t/b come off. Be sure to label all vacuum connections - don't rely on memory. Drain coolant, may want to remove radiator for working room. Remove front accessories - lay them off to the side without disconnecting hoses. Distributor out, balancer off (need a puller), water pump off, front cover off, lower intake off, valve covers off, rockers off, pushrods out.
Pull your lifters out - some aftermarket heads have to be removed to get the lifters out - then loosen cam bolt, and remove timing chain/gears (may have to use a puller to get them started). Carefully remove cam being careful not to damage cam bearings (I put the cam gear back on to give me leverage, some people insert a long bolt).
Install new cam, degree it to be sure it's timed properly, measure p to v clearance to be sure you're ok (shouldn't be a problem with stock heads/pistons), then everything else goes back together. Prime the motor through the dizzy hole til you get fresh oil up all the pushrods. Be sure to reset timing with timing light after you get it running. Tough spots are carefully sealing intake, and reinstalling the front cover with it's 3-way sealing issues (front of block, back of water pump, oil pan and half-seal around shaft snout).
Good luck with it.